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Menamo T, Kassahun B, Borrell AK, Jordan DR, Tao Y, Hunt C, Mace E. Genetic diversity of Ethiopian sorghum reveals signatures of climatic adaptation. Theor Appl Genet 2021; 134:731-742. [PMID: 33341904 DOI: 10.1007/s00122-020-03727-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 11/06/2020] [Indexed: 05/23/2023]
Abstract
A large collection of Ethiopian sorghum landraces, characterized by agro-ecology and racial-group, was found to contain high levels of diversity and admixture, with significant SNP associations identified for environmental adaptation. Sorghum [Sorghum bicolor L. (Moench)] is a major staple food crop in Ethiopia, exhibiting extensive genetic diversity with adaptations to diverse agroecologies. The environmental and climatic drivers, as well as the genomic basis of adaptation, are poorly understood in Ethiopian sorghum and are critical elements for the development of climate-resilient crops. Exploration of the genome-environment association (GEA) is important for identifying adaptive loci and predicting phenotypic variation. The current study aimed to better understand the GEA of a large collection of Ethiopian sorghum landraces (n = 940), characterized with genome-wide SNP markers, to investigate key traits related to adaptation to temperature, precipitation and altitude. The Ethiopian sorghum landrace collection was found to consist of 12 subpopulations with high levels of admixture (47%), representing all the major racial groups of cultivated sorghum with the exception of kafir. Redundancy analysis indicated that agroecology explained up to 10% of the total SNP variation, and geographical location up to 6%. GEA identified 18 significant SNP markers for environmental variables. These SNPs were found to be significantly enriched (P < 0.05) for a priori QTL for drought and cold adaptation. The findings from this study improve our understanding of the genetic control of adaptive traits in Ethiopian sorghum. Further, the Ethiopian sorghum germplasm collection provides sources of adaptation to harsh environments (cold and/or drought) that could be deployed in breeding programs globally for abiotic stress adaptation.
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Affiliation(s)
- T Menamo
- College of Agriculture and Veterinary Medicine, Jimma University, P.O. Box 307, Jimma, Ethiopia
| | - B Kassahun
- College of Agriculture and Veterinary Medicine, Jimma University, P.O. Box 307, Jimma, Ethiopia
| | - A K Borrell
- Queensland Alliance for Agriculture and Food Innovation (QAAFI), Hermitage Research Facility, University of Queensland, Warwick, QLD, 4370, Australia
| | - D R Jordan
- Queensland Alliance for Agriculture and Food Innovation (QAAFI), Hermitage Research Facility, University of Queensland, Warwick, QLD, 4370, Australia
| | - Y Tao
- Queensland Alliance for Agriculture and Food Innovation (QAAFI), Hermitage Research Facility, University of Queensland, Warwick, QLD, 4370, Australia
| | - C Hunt
- Department of Agriculture and Fisheries, Hermitage Research Facility, Agri-Science Queensland, Warwick, QLD, 4370, Australia
| | - E Mace
- Queensland Alliance for Agriculture and Food Innovation (QAAFI), Hermitage Research Facility, University of Queensland, Warwick, QLD, 4370, Australia.
- Department of Agriculture and Fisheries, Hermitage Research Facility, Agri-Science Queensland, Warwick, QLD, 4370, Australia.
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Frederiks TM, Christopher JT, Sutherland MW, Borrell AK. Post-head-emergence frost in wheat and barley: defining the problem, assessing the damage, and identifying resistance. J Exp Bot 2015; 66:3487-98. [PMID: 25873656 DOI: 10.1093/jxb/erv088] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Radiant frost is a significant production constraint to wheat (Triticum aestivum) and barley (Hordeum vulgare), particularly in regions where spring-habit cereals are grown through winter, maturing in spring. However, damage to winter-habit cereals in reproductive stages is also reported. Crops are particularly susceptible to frost once awns or spikes emerge from the protection of the flag leaf sheath. Post-head-emergence frost (PHEF) is a problem distinct from other cold-mediated production constraints. To date, useful increased PHEF resistance in cereals has not been identified. Given the renewed interest in reproductive frost damage in cereals, it is timely to review the problem. Here we update the extent and impacts of PHEF and document current management options to combat this challenge. We clarify terminology useful for discussing PHEF in relation to chilling and other freezing stresses. We discuss problems characterizing radiant frost, the environmental conditions leading to PHEF damage, and the effects of frost at different growth stages. PHEF resistant cultivars would be highly desirable, to both reduce the incidence of direct frost damage and to allow the timing of crop maturity to be managed to maximize yield potential. A framework of potential adaptation mechanisms is outlined. Clarification of these critical issues will sharpen research focus, improving opportunities to identify genetic sources for improved PHEF resistance.
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Affiliation(s)
- T M Frederiks
- Department of Agriculture and Fisheries Queensland, Leslie Research Facility, PO Box 2282 Toowoomba, QLD 4350, Australia The University of Southern Queensland, Centre for Crop Health, West St, Toowoomba, QLD 4370, Australia
| | - J T Christopher
- The University of Queensland, Queensland Alliance for Agriculture and Food Innovation, Leslie Research Facility, PO Box 2282 Toowoomba, QLD 4350, Australia
| | - M W Sutherland
- The University of Southern Queensland, Centre for Crop Health, West St, Toowoomba, QLD 4370, Australia
| | - A K Borrell
- The University of Queensland, Queensland Alliance for Agriculture and Food Innovation, Hermitage Research Facility, 604 Yangan Road, via Warwick, QLD 4370, Australia
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Frederiks TM, Christopher JT, Harvey GL, Sutherland MW, Borrell AK. Current and emerging screening methods to identify post-head-emergence frost adaptation in wheat and barley. J Exp Bot 2012; 63:5405-16. [PMID: 22888127 DOI: 10.1093/jxb/ers215] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Cereal crops can suffer substantial damage if frosts occur at heading. Identification of post-head-emergence frost (PHEF) resistance in cereals poses a number of unique and difficult challenges. Many decades of research have failed to identify genotypes with PHEF resistance that could offer economically significant benefit to growers. Research and breeding gains have been limited by the available screening systems. Using traditional frost screening systems, genotypes that escape frost injury in trials due to spatial temperature differences and/or small differences in phenology can be misidentified as resistant. We believe that by improving techniques to minimize frost escapes, such 'false-positive' results can be confidently identified and eliminated. Artificial freezing chambers or manipulated natural frost treatments offer many potential advantages but are not yet at the stage where they can be reliably used for frost screening in breeding programmes. Here we describe the development of a novel photoperiod gradient method (PGM) that facilitates screening of genotypes of different phenology under natural field frosts at matched developmental stages. By identifying frost escapes and increasing the efficiency of field screening, the PGM ensures that research effort can be focused on finding genotypes with improved PHEF resistance. To maximize the likelihood of identifying PHEF resistance, we propose that the PGM form part of an integrated strategy to (i) source germplasm;(ii) facilitate high throughput screening; and (iii) permit detailed validation. PGM may also be useful in other studies where either a range of developmental stages and/or synchronized development are desired.
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Affiliation(s)
- T M Frederiks
- Queensland Department of Agriculture, Fisheries and Forestry (DAFFQ), Leslie Research Facility, PO Box 2282 Toowoomba, QLD, 4350, Australia.
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Christopher JT, Manschadi AM, Hammer GL, Borrell AK. Developmental and physiological traits associated with high yield and stay-green phenotype in wheat. ACTA ACUST UNITED AC 2008. [DOI: 10.1071/ar07193] [Citation(s) in RCA: 134] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Water availability is a key limiting factor in wheat production in the northern grain belt of Australia. Varieties with improved adaptation to such conditions are actively sought. The CIMMYT wheat line SeriM82 has shown a significant yield advantage in multi-environment screening trials in this region. The objective of this study was to identify the physiological basis of the adaptive traits underpinning this advantage. Six detailed experiments were conducted to compare the growth, development, and yield of SeriM82 with that of the adapted cultivar, Hartog. The experiments were undertaken in field environments that represented the range of moisture availability conditions commonly encountered by winter crops grown on the deep Vertosol soils of this region. The yield of SeriM82 was 6–28% greater than that of Hartog, and SeriM82 exhibited a stay-green phenotype by maintaining green leaf area longer during the grain-filling period in all environments where yield was significantly greater than Hartog. However, where the availability of deep soil moisture was limited, SeriM82 failed to exhibit significantly greater yield or to express the stay-green phenotype. Thus, the stay-green phenotype was closely associated with the yield advantage of SeriM82. SeriM82 also exhibited higher mean grain mass than Hartog in all environments. It is suggested that small differences in water use before anthesis, or greater water extraction from depth after anthesis, could underlie the stay-green phenotype. The inability of SeriM82 to exhibit stay-green and higher yield where deep soil moisture was depleted indicates that extraction of deep soil moisture is important.
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Van Cooten DE, Borrell AK. Enhancing food security in semi-arid eastern Indonesia through permanent raised-bed cropping: a review. ACTA ACUST UNITED AC 1999. [DOI: 10.1071/ea99054] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Summary. Much of south-eastern Indonesia is mountainous
and characterised by a semi-arid tropical environment. Soil erosion is a
significant environmental problem facing the region, affecting both
productivity of the land and water quality. The challenge for the region is to
secure year-round food production in such a fragile environment. More than
90% of rain falls in a distinct wet season between November and April.
Therefore, cropping in this region is dependent on matching crop growth with
water supply. In particular, crop production depends on the efficient use of
rainfall during the wet season, including avoidance of waterlogging, and
efficient use of stored soil water during the dry season.
This paper summarises the results of a series of experiments undertaken in
West Timor, Indonesia, between 1993 and 1999 aimed at developing a raised-bed
cropping system. The objective of these studies was to better utilise the more
fertile alluvial soils that are often susceptible to waterlogging during the
wet season, allowing a range of crops to be grown in addition to rice.
Raised beds of height 0.2 m and width 1.5 m were constructed either manually
or with an 8.5 hp two-wheeled hand tractor. A range of crops including
soybeans, sorghum, maize, pigeon pea, yam bean and cassava were successfully
grown on raised beds in the wet season in addition to rice, indicating that
raised-bed technology overcomes the constraints of waterlogging in the wet
season. Soybeans grew particularly well on raised beds, with December-sown
crops producing almost twice the yield of January-sown crops (2.6
v. 1.4 t/ha). For rice and soybeans, early sown
crops were better able to match growth with water supply, thereby avoiding
end-of-season drought. Early sowing and harvesting of wet season crops enables
a drought-resistant crop such as sorghum to be planted in lateMarch or early
April, utilising the stored soil moisture for grain production and also
maintaining ground cover in the dry season.
It is argued that cropping systems based on permanent raised beds can reduce
erosion in 2 ways. First, raised beds are a permanent structure and, with the
inter-cropping and relay-cropping proposed, crops can provide all-year ground
cover in lowland areas. Second, if sufficient food and cash crops are grown on
raised beds to meet the basic needs of subsistence farmers, then upland
cropping on steep slopes can be replaced by a variety of tree species,
providing additional food, fodder, firewood and medicines. Together, these
strategies have the capacity to enhance food production and security in the
semi-arid areas of eastern Indonesia.
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Borrell AK, Garside AL, Fukai S, Reid DJ. Season, nitrogen rate, and plant type affect nitrogen uptake and nitrogen use efficiency in rice. ACTA ACUST UNITED AC 1998. [DOI: 10.1071/a97057] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Studies were undertaken in the Burdekin River Irrigation Area of northern
Australia to improve the efficiency of nitrogen (N) use for rice
(Oryza sativa L.) production. The aim was to maximise
grain yield by optimising its functional components: N uptake, efficiency of N
use for dry matter production (NUEdm), and harvest index
(HI). The effiects of season (wet and dry), N rate (0, 70, 140, 210, and 280
kg/ha), and plant type (maturity and stature) on N uptake,
NUEdm, and HI were examined in 2 wet and 2 dry seasons.
Leaf area development was closely related to N uptake. In the wet season,
genotypes had similar rates of increase in leaf area index (LAI) with N uptake
but differed in the level of LAI (curves were parallel).
In the dry season, the relationship between N uptake and LAI was different for
each genotype (curves not parallel). In both seasons cv.
Newbonnet generally had a lower LAI per unit N uptake (i.e. leaf area
production was not excessive) than cvv. Lemont and Starbonnet. Dry matter
production and grain yield were also closely related to N uptake. At low
levels of N availability (N uptake <100 kg/ha) tissue N concentrations
were low and both total above-ground dry mass (AGDM) and grain yield were
linearly related to N uptake. As N availability increased, N uptake and tissue
N concentration increased, resulting in a deviation of the AGDM and grain
yield curves from the linear at about 100 kg/haN uptake. This finally
resulted in AGDM and grain yield plateauing at around 200 kg/ha N uptake.
Above this level some factors other than N availability limited yield.
Seasonal differences in N uptake, NUEdm, and HI were
observed. Seasonal variation in the response of grain yield to N uptake was
found. There was a trend for higher N uptake in the absence of fertiliser
application in the wet than the dry season, and the recovery fraction was less
for N rates >140 kg/ha in all seasons, i.e. fertiliser N uptake
efficiency declined with increasing N rate. Nitrogen was used more effectively
by the rice crop to produce grain compared with non-grain parts when average
daily mean temperatures were lower during the period between panicle
initiation and anthesis.
Genotypic variation was found in N uptake, NUEdm, and
HI. The ability to capture these components in crop improvement programs
depends on the extent to which genetic linkages between N uptake and both
NUEdm and HI can be broken. While our data suggest that
N uptake is generally negatively correlated with both
NUEdm and HI, there is some evidence that these linkages
can be broken. For example, the fact that HIdid not change with increasing N
uptake in Lemont and, to a lesser extent, in Newbonnet suggests that HI does
not always decline with increasing N uptake. The example of Newbonnet suggests
that, to some extent, it is possible to increase yield by increasing each of
the functional components independently within a specific genotype.
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