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The 'microbiome counterattack': Insights on the soil and root-associated microbiome in diverse chickpea and lentil genotypes after an erratic rainfall event. ENVIRONMENTAL MICROBIOLOGY REPORTS 2023; 15:459-483. [PMID: 37226644 PMCID: PMC10667653 DOI: 10.1111/1758-2229.13167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2023] [Accepted: 05/05/2023] [Indexed: 05/26/2023]
Abstract
Legumes maintain soil fertility thanks to their associated microbiota but are threatened by climate change that causes soil microbial community structural and functional modifications. The core microbiome associated with different chickpea and lentil genotypes was described after an unexpected climatic event. Results showed that chickpea and lentil bulk soil microbiomes varied significantly between two sampling time points, the first immediately after the rainfall and the second 2 weeks later. Rhizobia were associated with the soil of the more productive chickpea genotypes in terms of flower and fruit number. The root-associated bacteria and fungi were surveyed in lentil genotypes, considering that several parcels showed disease symptoms. The metabarcoding analysis revealed that reads related to fungal pathogens were significantly associated with one lentil genotype. A lentil core prokaryotic community common to all genotypes was identified as well as a genotype-specific one. A higher number of specific bacterial taxa and an enhanced tolerance to fungal diseases characterized a lentil landrace compared to the commercial varieties. This outcome supported the hypothesis that locally adapted landraces might have a high recruiting efficiency of beneficial soil microbes.
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Yield and related traits of three legume crops grown in olive-based agroforestry under an intense drought in the South Mediterranean. Saudi J Biol Sci 2023; 30:103597. [PMID: 36910463 PMCID: PMC9999212 DOI: 10.1016/j.sjbs.2023.103597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 01/18/2023] [Accepted: 02/08/2023] [Indexed: 02/17/2023] Open
Abstract
Heat and drought stresses have become more frequent and intense in the Mediterranean, strongly influencing arable crop phenology, growth, and grain yield. Agroforestry systems can effectively buffer the adverse climate conditions and stabilize or even increase crop yield under climate change. However, the positive effects of agroforestry remain uncertain due to the possible intense competition between trees and crops, especially for legume crops that have been less studied than cereals in such context. This study aimed to assess the response of the phenology, growth, grain yield, and yield-related traits of chickpea (Cicer arietinum), faba bean (Vicia faba), and lentil (Lens culinaris) to olive-based agroforestry (AFS) as compared to sole crops system (SCS) in the South of the Mediterranean. We conducted a field experiment during two growing seasons marked by an intense drought, either at the beginning (year 1) or at the end (year 2) of the crop cycle. Crop growth and yield were lower in year 1 than in year 2, reflecting the adverse growing conditions caused by the early drought. They were also lower in AFS than in SCS for both years, indicating that trees had competitive effects on crops. In year 1, the yield loss of grains in AFS was 66 % for lentil, 47 % for chickpea, and 43 % for faba bean compared to SCS, confirming the greater shade sensitivity of lentil. In year 2, the reduction was significantly smaller and was about 46 %, 34 %, 38 % for lentil, chickpea and, faba bean, respectively. The number of pods and grains were the most affected yield components by agroforestry and drought timing across the three legumes crops. Similar responses were found when comparing crops at different distances to trees within the AFS field. Crops generally had lower biomass and yield, explained by fewer pods and grains, on the northern side of trees compared to the southern side of trees or the middle of tree inter-rows, causing significant spatial heterogeneity in crops. However, lentil and chickpea had a positive response to shade during the early drought year while a negative response during the late drought year, suggesting that the benefits of the microclimate created by olive trees express depending on drought timing and crop physiology. Our study supports legume integration into AFS, suggesting that chickpea should be considered during high-stress conditions, while faba bean should be preferred during low-stress conditions.
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Bambara groundnut: an exemplar underutilised legume for resilience under climate change. PLANTA 2019; 250:803-820. [PMID: 31267230 DOI: 10.1007/s00425-019-03191-6] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Accepted: 05/16/2019] [Indexed: 05/18/2023]
Abstract
Bambara groundnut has the potential to be used to contribute more the climate change ready agriculture. The requirement for nitrogen fixing, stress tolerant legumes is clear, particularly in low input agriculture. However, ensuring that existing negative traits are tackled and demand is stimulated through the development of markets and products still represents a challenge to making greater use of this legume. World agriculture is currently based on very limited numbers of crops, representing a significant risk to food supplies, particularly in the face of climate change which is expected to increase the frequency of extreme events. Minor and underutilised crops can help to develop a more resilient and nutritionally dense future agriculture. Bambara groundnut [Vigna subterranea (L.) Verdc.[, as a drought resistant, nitrogen-fixing, legume has a role to play. However, as with most underutilised crops, there are significant gaps in knowledge and also negative traits such as 'hard-to-cook' and 'photoperiod sensitivity to pod filling' associated with the crop which future breeding programmes and processing methods need to tackle, to allow it to make a significant contribution to the well-being of future generations. The current review assesses these factors and also considers what are the next steps towards realising the potential of this crop.
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Altered Expression of an FT Cluster Underlies a Major Locus Controlling Domestication-Related Changes to Chickpea Phenology and Growth Habit. FRONTIERS IN PLANT SCIENCE 2019; 10:824. [PMID: 31333691 PMCID: PMC6616154 DOI: 10.3389/fpls.2019.00824] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Accepted: 06/07/2019] [Indexed: 05/20/2023]
Abstract
Flowering time is a key trait in breeding and crop evolution, due to its importance for adaptation to different environments and for yield. In the particular case of chickpea, selection for early phenology was essential for the successful transition of this species from a winter to a summer crop. Here, we used genetic and expression analyses in two different inbred populations to examine the genetic control of domestication-related differences in flowering time and growth habit between domesticated chickpea and its wild progenitor Cicer reticulatum. A single major quantitative trait locus for flowering time under short-day conditions [Days To Flower (DTF)3A] was mapped to a 59-gene interval on chromosome three containing a cluster of three FT genes, which collectively showed upregulated expression in domesticated relative to wild parent lines. An equally strong association with growth habit suggests a pleiotropic effect of the region on both traits. These results indicate the likely molecular explanation for the characteristic early flowering of domesticated chickpea, and the previously described growth habit locus Hg. More generally, they point to de-repression of this specific gene cluster as a conserved mechanism for achieving adaptive early phenology in temperate legumes.
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Abstract
The water footprint (WF) of crop production is a friendly approach for the analysis of water resource consumption in agricultural production systems. This study assessed the inter-annual variability of the total WF of three types of main crops, namely, cereal (i.e., spring wheat and barley), oilseed (i.e., canola and sunflower) and pulse (i.e., lentils and chickpea), from the perspective of yield and protein. It also determined the major factors that influence the WFs in Saskatchewan province of Canada. Over the period of 1965–2014, the annual precipitation in Saskatchewan fluctuated considerably but increased slightly with time. The grain yield-based WF ranged between 1.08 and 1.80, 0.90 and 1.38, 1.71 and 2.58, 1.94 and 4.28, 1.47 and 2.37, and 1.39 and 1.79 m3 kg−1; whereas the protein yield-based WF ranged between 7.69 and 10.44, 8.27 and 16.47, 3.79 and 7.75, 4.86 and 11.17, 5.09 and 7.42, and 5.51 and 10.69 m3 kg−1 for spring wheat, barley, canola, sunflower, lentils, and chickpea, respectively. All the WFs of crops generally decreased with time, which could be attributed to precipitation factors. In addition, the scientific and technological progress and agricultural inputs also evidently influenced the grain yield-based WFs of all crops. Pulse crops had a higher grain yield-based WF (an average of 1.59 m3 kg−1 for pulse crops and 1.18 m3 kg−1 for cereal crops) but a lower protein yield-based WF (an average of 6.58 m3 kg−1 for pulse crops and 9.25 m3 kg−1 for cereal crops) than cereal crops. Under conditions of improved protein consumption and healthy living in the future, pulse crops may be a preferred crop.
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Exploring Niches for Short-Season Grain Legumes in Semi-Arid Eastern Kenya - Coping with the Impacts of Climate Variability. FRONTIERS IN PLANT SCIENCE 2017; 8:699. [PMID: 28536585 PMCID: PMC5422554 DOI: 10.3389/fpls.2017.00699] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 04/18/2017] [Indexed: 05/15/2023]
Abstract
Climate variability is the major risk to agricultural production in semi-arid agroecosystems and the key challenge to sustain farm livelihoods for the 500 million people who inhabit these areas worldwide. Short-season grain legumes have great potential to address this challenge and help to design more resilient and productive farming systems. However, grain legumes display a great diversity and differ widely in growth, development, and resource use efficiency. Three contrasting short season grain legumes common bean (Phaseolus vulgaris L.), cowpea (Vigna unguiculata (L.) Walp.] and lablab [Lablab purpureus (L.) Sweet] were selected to assess their agricultural potential with respect to climate variability and change along the Machakos-Makueni transect in semi-arid Eastern Kenya. This was undertaken using measured data [a water response trial conducted during 2012/13 and 2013/14 in Machakos, Kenya] and simulated data using the Agricultural Production System sIMulator (APSIM). The APSIM crop model was calibrated and validated to simulate growth and development of short-season grain legumes in semi-arid environments. Water use efficiency (WUE) was used as indicator to quantify the production potential. The major traits of adaptation include early flowering and pod and seed set before the onset of terminal drought. Early phenology together with adapted canopy architecture allowed more optimal water use and greater partitioning of dry matter into seed (higher harvest index). While common bean followed a comparatively conservative strategy of minimizing water loss through crop transpiration, the very short development time and compact growth habit limited grain yield to rarely exceed 1,000 kg ha-1. An advantage of this strategy was relatively stable yields independent of in-crop rainfall or season length across the Machakos-Makueni transect. The growth habit of cowpea in contrast minimized water loss through soil evaporation with rapid ground cover and dry matter production, reaching very high grain yields at high potential sites (3,000 kg ha-1) but being highly susceptible to in-season drought. Lablab seemed to be best adapted to dry environments. Its canopy architecture appeared to be best in compromising between the investment in biomass as a prerequisite to accumulate grain yield by minimizing water loss through soil evaporation and crop transpiration. This lead to grain yields of up to 2,000 kg ha-1 at high potential sites and >1,000 kg ha-1 at low potential sites. The variance of observed and simulated WUE was high and no clear dependency on total rainfall alone was observed for all three short-season grain legumes, highlighting that pattern of water use is also important in determining final WUEbiomass and WUEgrain. Mean WUEgrain was lowest for cowpea (1.5-3.5 kggrain ha-1 mm-1) and highest for lablab (5-7 kggrain ha-1 mm-1) reflecting the high susceptibility to drought of cowpea and the good adaptation to dry environments of lablab. Results highlight that, based on specific morphological, phonological, and physiological characteristics, the three short-season grain legumes follow different strategies to cope with climate variability. The climate-smart site-specific utilization of the three legumes offers promising options to design more resilient and productive farming systems in semi-arid Eastern Kenya.
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Root traits confer grain yield advantages under terminal drought in chickpea ( Cicer arietinum L.). FIELD CROPS RESEARCH 2017; 201:146-161. [PMID: 28163361 PMCID: PMC5221670 DOI: 10.1016/j.fcr.2016.11.004] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Revised: 11/11/2016] [Accepted: 11/13/2016] [Indexed: 05/24/2023]
Abstract
Chickpea, the second most important legume crop, suffers major yield losses by terminal drought stress (DS). Stronger root system is known to enhance drought yields but this understanding remains controversial. To understand precisely the root traits contribution towards yield, 12 chickpea genotypes with well-known drought response were field evaluated under drought and optimal irrigation. Root traits, such as root length density (RLD), total root dry weight (RDW), deep root dry weight (deep RDW) and root:shoot ratio (RSR), were measured periodically by soil coring up to 1.2 m soil depth across drought treatments. Large variations were observed for RLD, RDW, deep RDW and RSR in both the drought treatments. DS increased RLD below 30 cm soil depth, deep RDW, RSR but decreased the root diameter. DS increased the genetic variation in RDW more at the penultimate soil depths. Genetic variation under drought was the widest for RLD ∼50 DAS, for deep RDW ∼50-75 DAS and for RSR at 35 DAS. Genotypes ICC 4958, ICC 8261, Annigeri, ICC 14799, ICC 283 and ICC 867 at vegetative stage and genotypes ICC 14778, ICCV 10, ICC 3325, ICC 14799 and ICC 1882 at the reproductive phase produced greater RLD. Path- and correlation coefficients revealed strong positive contributions of RLD after 45 DAS, deep RDW at vicinity of maturity and RSR at early podfill stages to yield under drought. Breeding for the best combination of profuse RLD at surface soil depths, and RDW at deeper soil layers, was proposed to be the best selection strategy, for an efficient water use and an enhanced terminal drought tolerance in chickpea.
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Expounding the Value of Grain Legumes in the Semi- and Arid Tropics. SUSTAINABILITY 2017. [DOI: 10.3390/su9010060] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Review: An integrated framework for crop adaptation to dry environments: Responses to transient and terminal drought. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2016; 253:58-67. [PMID: 27968997 DOI: 10.1016/j.plantsci.2016.09.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Revised: 09/16/2016] [Accepted: 09/20/2016] [Indexed: 05/09/2023]
Abstract
As the incidence of water deficit and heat stress increases in many production regions there is an increasing requirement for crops adapted to these stresses. Thus it is essential to match water supply and demand, particularly during grain-filling. Here we integrate Grime's ecological strategies approach with traditional drought resistance/yield component frameworks describing plant responses to water deficit. We demonstrate that water use is a function of both short and longer term trade-offs between competing demands for carbon. Agricultural crop adaptation is based on escape. Rapid growth rates and high reproductive investment maximize yield, and stress is avoided through a closely regulated, climate-appropriate annual phenology. Crops have neither the resources nor morphological capacity to withstand long periods of intense water deficit. Thus, under terminal drought, yield potential is traded off against drought escape, such that drought postponing and/or tolerance traits which extend the growing season and/or divert source from reproductive sinks are maladaptive. However, these traits do play a supporting role against transient water deficits, allowing longer season cultivars to survive by mining water through deeper roots, or restricting transpiration. Recognizing these trade-offs made within escape-strategy limits will allow breeders to integrate complementary adaptive traits to transient and terminal water deficits.
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A global experimental dataset for assessing grain legume production. Sci Data 2016; 3:160084. [PMID: 27676125 PMCID: PMC5037976 DOI: 10.1038/sdata.2016.84] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Accepted: 08/17/2016] [Indexed: 11/29/2022] Open
Abstract
Grain legume crops are a significant component of the human diet and animal feed and have an important role in the environment, but the global diversity of agricultural legume species is currently underexploited. Experimental assessments of grain legume performances are required, to identify potential species with high yields. Here, we introduce a dataset including results of field experiments published in 173 articles. The selected experiments were carried out over five continents on 39 grain legume species. The dataset includes measurements of grain yield, aerial biomass, crop nitrogen content, residual soil nitrogen content and water use. When available, yields for cereals and oilseeds grown after grain legumes in the crop sequence are also included. The dataset is arranged into a relational database with nine structured tables and 198 standardized attributes. Tillage, fertilization, pest and irrigation management are systematically recorded for each of the 8,581 crop*field site*growing season*treatment combinations. The dataset is freely reusable and easy to update. We anticipate that it will provide valuable information for assessing grain legume production worldwide.
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Nonlinear temperature effects indicate severe damages to U.S. crop yields under climate change. Proc Natl Acad Sci U S A 2009. [PMID: 19717432 DOI: 10.1007/s13593-011-0021-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2023] Open
Abstract
The United States produces 41% of the world's corn and 38% of the world's soybeans. These crops comprise two of the four largest sources of caloric energy produced and are thus critical for world food supply. We pair a panel of county-level yields for these two crops, plus cotton (a warmer-weather crop), with a new fine-scale weather dataset that incorporates the whole distribution of temperatures within each day and across all days in the growing season. We find that yields increase with temperature up to 29 degrees C for corn, 30 degrees C for soybeans, and 32 degrees C for cotton but that temperatures above these thresholds are very harmful. The slope of the decline above the optimum is significantly steeper than the incline below it. The same nonlinear and asymmetric relationship is found when we isolate either time-series or cross-sectional variations in temperatures and yields. This suggests limited historical adaptation of seed varieties or management practices to warmer temperatures because the cross-section includes farmers' adaptations to warmer climates and the time-series does not. Holding current growing regions fixed, area-weighted average yields are predicted to decrease by 30-46% before the end of the century under the slowest (B1) warming scenario and decrease by 63-82% under the most rapid warming scenario (A1FI) under the Hadley III model.
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Abstract
Chickpea (Cicer arietinum L.) has been traditionally grown in India but is a relatively new export crop in Australia where its cultivation is expanding into new areas. The objective of this study was to identify homoclimes (i.e. similar chickpea-growing environments) in the major chickpea-growing areas of the 2 countries, using the Agricultural Production Systems Simulator (APSIM) chickpea model. The model, which processes climatic, soil, and plant information on a daily time step, was first validated and then used to simulate flowering, maturity, and grain yield of Amethyst, a mid-season cultivar, and Barwon, a full-season cultivar, on low (100 mm), medium (150 mm), and high (190 mm) water-holding capacity soils, using historical climatic data of 67 Australian and 24 Indian locations. The mean of annual outputs of flowering, maturity, and grain yield of the 2 cultivars on 3 soils was then clustered using Ward’s hierarchical complete linkage clustering procedure. At a 90% level of similarity, all the locations could be grouped into 6 homoclime clusters. The Australian locations appeared more diverse as they were present in all the clusters, whereas the Indian locations were present only in clusters 1, 2, and 6. While there were clear geographical patterns of spread of these clusters, in Australia they were not entirely related to latitude. The cluster 1 and 2 locations, which represent the largest chickpea-growing area in Australia, had homoclime locations in common with northern India. The clustering of locations appeared generally consistent with the known adaptation of chickpea in different environments of the 2 countries and therefore suggests that the methodology could be potentially used for complementing conventional approaches of introducing or exchanging germplasm, as well as determining appropriateness of breeding/testing sites.
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Assessing the sustainability of wheat-based cropping systems using APSIM: model parameterisation and evaluation. ACTA ACUST UNITED AC 2007. [DOI: 10.1071/ar06186] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Assessing the sustainability of crop and soil management practices in wheat-based rotations requires a well-tested model with the demonstrated ability to sensibly predict crop productivity and changes in the soil resource. The Agricultural Production Systems Simulator (APSIM) suite of models was parameterised and subsequently used to predict biomass production, yield, crop water and nitrogen (N) use, as well as long-term soil water and organic matter dynamics in wheat/chickpea systems at Tel Hadya, north-western Syria. The model satisfactorily simulated the productivity and water and N use of wheat and chickpea crops grown under different N and/or water supply levels in the 1998–99 and 1999–2000 experimental seasons. Analysis of soil-water dynamics showed that the 2-stage soil evaporation model in APSIM’s cascading water-balance module did not sufficiently explain the actual soil drying following crop harvest under conditions where unused water remained in the soil profile. This might have been related to evaporation from soil cracks in the montmorillonitic clay soil, a process not explicitly simulated by APSIM. Soil-water dynamics in wheat–fallow and wheat–chickpea rotations (1987–98) were nevertheless well simulated when the soil water content in 0–0.45 m soil depth was set to ‘air dry’ at the end of the growing season each year. The model satisfactorily simulated the amounts of NO3-N in the soil, whereas it underestimated the amounts of NH4-N. Ammonium fixation might be part of the soil mineral-N dynamics at the study site because montmorillonite is the major clay mineral. This process is not simulated by APSIM’s nitrogen module. APSIM was capable of predicting long-term trends (1985–98) in soil organic matter in wheat–fallow and wheat–chickpea rotations at Tel Hadya as reported in literature. Overall, results showed that the model is generic and mature enough to be extended to this set of environmental conditions and can therefore be applied to assess the sustainability of wheat–chickpea rotations at Tel Hadya.
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Physiological and seed yield responses to water deficits among lentil genotypes from diverse origins. ACTA ACUST UNITED AC 2006. [DOI: 10.1071/ar05204] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The effect of water deficits at 2 growth stages on the physiology and growth of lentil (Lens culinaris Medikus subsp. culinaris) genotypes bred/selected for 3 regions was examined in a glasshouse experiment. The water regimes imposed were: (i) a well-watered control, (ii) water withheld at flowering, from 72 to 93 days after sowing (DAS), and (iii) water withheld from podding (93 DAS) to maturity. The genotypes were a West Asian genotype released in Australia (Cassab), 2 South Asian Nepali cultivars (Khajura 2 and Simal), and 3 crossbreds between West Asian and South Asian parents (ILL 6829, ILL 7979, and ILL 7982). ILL 7979 and Simal had significantly greater total dry matter, water use, seed yield, number of pods and seeds per plant, and harvest index (HI) than the other genotypes under well-watered conditions. Water deficits reduced seed yield by up to 60% in the crossbreds and the South Asian cultivar, Simal. However, seed yield was increased by the water deficit at flowering and the water deficit at podding in the West Asian genotype, Cassab, and the South Asian genotype, Khajura 2, respectively. In the other genotypes, withholding water at flowering or podding reduced leaf area (48–55%), total dry matter (32–50%), flower production (22–55%), and number of pods and seeds (27–66%), with significantly higher flower drop and empty pods when water was withheld. The higher seed yield in Cassab and Khajura 2 when water was withheld was related to the production of more flowers and the maintenance of pod and seed set when they were re-watered after the period of water deficit.
When water was withheld during flowering, the West Asian genotype Cassab and the crossbred ILL 6829 used less water and hence maintained a high leaf water potential (ψleaf), whereas ψleaf decreased earlier to lower values in the crossbred ILL 7979 and the South Asian genotypes Khajura 2 and Simal. There were no significant differences in leaf net photosynthesis (PN), or stomatal conductance (gS), among genotypes during flowering and early podding, but PN and gS were reduced by 22–38 and 19–67%, respectively, when water was withheld. The lower ψleaf in ILL 7979, Simal, and Khajura 2 induced greater osmotic adjustment (OA) during the drying cycle at flowering, whereas there was no or little OA when water was withheld at podding. Variation in physiological traits (PN, gS, OA) under both watering regimes was not directly related to seed yield, but seed number was related to seed yield under both well-watered and water-deficit conditions.
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Crop production in the high rainfall zones of southern Australia — potential, constraints and opportunities. ACTA ACUST UNITED AC 2006. [DOI: 10.1071/ea05150] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Annual cropping has been expanding in the high rainfall zone of southern Australia. The higher rainfall and longer growing season compared with the traditional wheatbelt contribute to a much higher yield potential for major crops. Potential yields range from 5 to 8 t/ha for wheat and 3 to 5 t/ha for canola, although current crop yields are only about 50% of those potentials. The large yield gap between current and potential yields suggests that there is an opportunity to lift current yields. Both genetic constraints and subsoil constraints such as waterlogging, soil acidity, sodicity, and high soil strength contribute to the low yields. Waterlogging is a widespread hidden constraint to crop production in the region. Controlling waterlogging using a combination of raised beds and surface or subsurface drains is the first step to raise the productivity of the land. Increasing root growth into the subsoil remains a key to accessing more water and nutrients for high yield through early planting, deep ripping, liming and use of primer crops to ameliorate the subsoil. In order to realise the high yield potential, it is essential to achieve higher optimum dry matter at anthesis and high ear number through agronomic management, including early sowing with appropriate cultivars, a high seeding rate and application of adequate nitrogen along with other nutrients. Current cultivars of spring wheat may not fully utilise the available growing season and may have genetic limitations in sink capacity that constrain potential yield. Breeding or identification of long-season milling wheat cultivars that can fully utilise the longer growing season and with the ability to tolerate waterlogging and subsoil acidity, and with disease resistance, will give additional benefits. It is concluded that improving crop production in the high rainfall zone of southern Australia will require attention to overcoming soil constraints, particularly waterlogging, and the development of longer-season cultivars.
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Growth and seed yield of lentil (Lens culinaris Medikus) genotypes of West Asian and South Asian origin and crossbreds between the two under rainfed conditions in Nepal. ACTA ACUST UNITED AC 2005. [DOI: 10.1071/ar05050] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Nineteen diverse lentil genotypes, 8 originating from South Asia, 6 from West Asia, and 5 crossbreds using parents from South Asia and West Asia (or other Mediterranean environments), were evaluated for growth, phenology, yield, and yield components at Khumaltar in the mid-hill region of Nepal. Additionally, dry matter production, partitioning, root growth and water use of 8 selected genotypes from the 3 groups were measured at key phenological stages. The seed yield of the West Asian genotypes was only 330 kg/ha, whereas the South Asian genotypes produced a mean seed yield of 1270 kg/ha. The crossbreds had a significantly (P = 0.05) greater seed yield (1550 kg/ha) than the South Asian genotypes. The high seed yield of both the South Asian and crossbred genotypes was associated with rapid ground cover, early flowering and maturity, a long reproductive period, a greater number of seeds and pods, high total dry matter, greater harvest index, and high water use efficiency. West Asian genotypes, on the other hand, flowered 43 days later, matured 15 days later, and had a shorter reproductive period (by 22 days) than the crossbred and South Asian genotypes. The 23% greater seed yield in the crossbreds compared with the South Asian genotypes was the result of a similar increase in seed size (weight per seed).
There were no significant differences in total root length (mean 4.7 km/m2), root dry matter (mean 95.5 g/m2), or water use among the 3 groups during the major part of the growing period. There was a significant difference in total water use due to the longer growing season of the West Asian genotype ILL 7983 and its ability to use late-season rainfall. Maximum water use efficiencies for seed yield of 7.0 kg/ha.mm and for above-ground dry matter of 18.9 kg/ha.mm were comparable with those reported in India and the Mediterranean environments of south-western Australia and Syria.
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Genotype by environment studies across Australia reveal the importance of phenology for chickpea (Cicer arietinum L.) improvement. ACTA ACUST UNITED AC 2004. [DOI: 10.1071/ar04104] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Chickpea (Cicer arietinum L.) genotypes comprising released cultivars, advanced breeding lines, and landraces of Australian, Mediterranean basin, Indian, and Ethiopian origin were evaluated at 5 representative sites (Merredin, WA; Minnipa, SA; Walpeup, Vic.; Tamworth, NSW; Warwick, Qld) over 2 years. Data on plant stand, early vigour, phenology, productivity, and yield components were collected at each site.
Site yields ranged from 0.3 t/ha at Minnipa in 1999 to 3.5 t/ha at Warwick in 1999. Genotype by environment (G × E) interaction was highly significant. Principal components analysis revealed contrasting genotype interaction behaviour at dry, low-yielding sites (Minnipa 1999, Merredin 2000) and higher rainfall, longer growing-season environments (Tamworth 2000). Genotype clusters performing well under stress tended to yield well at all sites except Tamworth in 2000, and were characterised by early phenology and high harvest index, but were not different in terms of biomass or early vigour. Some of these traits were strongly influenced by germplasm origin. The material with earliest phenology came from Ethiopia, and southern and central India, with progressively later material from northern India and Australia, and finally the Mediterranean. There was a delay between the onset of flowering and podding at all sites, which was related to average temperatures immediately post-anthesis (r = –0.81), and therefore larger in early flowering material (>30 days at some sites). Harvest index was highest in Indian and Ethiopian germplasm, whereas crop height was greatest in Australian and Mediterranean accessions. Some consistently high yielding genotypes new to the Australian breeding program were identified (ICCV 10, BG 362), and the existing cultivar Lasseter was also confirmed to be very productive.
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