Genetic diversity among local mango (Mangifera indica L.) germplasm using morphological, biochemical and chloroplast DNA barcodes analyses

Postharvest quality and ripening behaviour of un-explored genotypes of Himalayan plain mango diversity

India is renowned for its mango diversity, with more than 1000 genotypes reported. However, the Himalayan plains bear some elite genotypes which supposed to bear high postharvest value, the systemic postharvest study of which is yet to be attempted. The aim of present study is to evaluate the postharvest quality and ripening behviour of these important genotypes. Thus, 15 un-explored mango genotypes of this region were selected and evaluated for ripening behaviour and detailed postharvest profiling via internal (total phenolic and total flavonoid content), nutritional attributes (Brix: acid ratio, total carotenoid concentration, ascorbic acid content and antioxidant activity), sensory evaluation, fruit softening enzymes (polygalactouronase, pectin methylesterase and lipoxygenase), shelf life attributes (respiration rate, physiological loss in weight and storage life in days) external attributes (fruit weight, fruit firmness, peel thickness, fruit shape and dry seed weight) and mineral contents (Calcium, potassium and phosphorous) under ambient storage (25 ± 4 °C and 65 ± 5 % RH). The results revealed that the highest total flavonoid content (682.40 μg g-1), ascorbic acid (46.88 mg 100 g-1) and antioxidant activity (4.84 μmol TE g-1) exhibited by 'Sukul'. The total phenolic content was recorded as the highest in 'Safed Malda' (510.42 μg GAE g-1 FW), and total carotenoid concentration was recorded as the highest in 'Sipiya' (7.30 mg 100 g-1) 'Zardalu' (7.04 mg 100 g-1) and 'Mithua' (6.98 mg 100 g-1). Interestingly, genotypes such as 'Sukul', Sipiya' and 'Krishna Bhog 'exhibited a 4-5 days higher storage life than other selected genotypes. Screened genotypes exhibited a high diversity of nutritional and biochemical contents. The results of this study bear practical utility for research (quality improvement programme) and the processing industry.

DNA barcode identification of cultivated and wild tropical fruit species

With the rapid growth of the fruit industry worldwide, it is important to assess adulteration to ensure the authenticity and the safety of fruit products. The DNA barcoding approach offers a quick and accurate way of identifying and authenticating species. In this study, we developed reference DNA barcodes (rbcL, ITS2, and trnH-psbA) for 70 cultivated and wild tropical fruit species, representing 43 genera and 26 families. In terms of species recoverability, rbcL has a greater recoverability (100%) than ITS2 (95.7%) and trnH-psbA (88.6%). We evaluated the performance of these barcodes in species discrimination using similarity BLAST, phylogenetic tree, and barcoding gap analyses. The efficiency of rbcL, ITS2, and trnH-psbA in discriminating species was 80%, 100%, and 93.6%, respectively. We employed a multigene-tiered approach for species identification, with the rbcL region used for primary differentiation and ITS2 or trnH-psbA used for secondary differentiation. The two-locus barcodes rbcL + ITS2 and rbcL + trnH-psbA demonstrated robustness, achieving species discrimination rates of 100% and 94.3% respectively. Beyond the conventional species identification method based on plant morphology, the developed reference barcodes will aid the fruit agroindustry and trade, by making fruit-based product authentication possible.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-023-03848-w.

Genome size, genetic diversity, and phenotypic variability imply the effect of genetic variation instead of ploidy on trait plasticity in the cross-pollinated tree species of mulberry

Elucidation of genome size (GS), genetic and phenotypic variation is the fundamental aspect of crop improvement programs. Mulberry is a cross-pollinated, highly heterozygous tree eudicot, and comprised of huge ploidy variation with great adaptability across the world. However, because of inadequate information on GS, ploidy-associated traits, as well as the correlation between genetic and phenotypic variation hinder the further improvement of mulberry. In this present research, a core set of 157 germplasm accessions belonging to eight accepted species of Morus including promising functional varieties were chosen to represent the genetic spectrum from the whole germplasm collection. To estimate the GS, accessions were subjected to flow cytometry (FCM) analysis and the result suggested that four different ploidies (2n = 2x, 3x, 4x, and 6x) with GS ranging from 0.72±0.005pg (S-30) to 2.89±0.015pg (M. serrata), accounting~4.01 fold difference. The predicted polyploidy was further confirmed with metaphase chromosome count. In addition, the genetic variation was estimated by selecting a representative morphologically, diverse population of 82 accessions comprised of all ploidy variations using simple sequence repeats (SSR). The estimated average Polymorphism Information Content (PIC) and expected heterozygosity showed high levels of genetic diversity. Additionally, three populations were identified by the model-based population structure (k = 3) with a moderate level of correlation between the populations and different species of mulberry, which imply the effect of genetic variation instead of ploidy on trait plasticity that could be a consequence of the high level of heterozygosity imposed by natural cross-pollination. Further, the correlation between ploidies, especially diploid and triploid with selected phenotypic traits was identified, however, consistency could not be defined with higher ploidy levels (>3x). Moreover, incite gained here can serve as a platform for future omics approaches to the improvement of mulberry traits.

Analysis of genetic diversity among Onobrychis accessions with high agronomic performance by simple sequence repeat (SSR) markers

BACKGROUND

Onobrychis viciifolia Scop. is a short-lived perennial cool-season legume used for forage production. It is a common native species in Asia Minor, especially in Turkey, the districts of the Caucasus, and the Caspian fringes. It can grow well in a broad range of climatic and soil types found in Asia, Europe, and North America. It is a non-bloating crop, making it suitable for use in both hay and pasture.

METHODS AND RESULTS

The aim was to assess the diversity of the 83 sainfoin genotypes selected based on their high agronomic performance from a germplasm collection evaluated in the experimental field of Tekirdag Namik Kemal University, Turkey. Ten nuclear simple sequence repeat (nSSR) primers (OVK036, OVK046, OVK094, OVK101, OVK125, OVK161, OVK174, OVM033, OVM061, and OVM125) were used in the study. All nSSR loci were found to be polymorphic and totally 92 alleles were detected. The mean observed number of alleles per locus was calculated as 9.2. Among the genetic diversity parameters, Shannon Index (I = 0.375), unbiased genetic diversity value (uh = 0.243), and mean polymorphic information content (PIC = 0.240) were calculated. The genetic distance value varied between 0.43 and 0.95. Based on the dendrogram built by the UPGMA clustering method using genetic distance values, it was observed that the studied sainfoin genotypes were divided into two main clusters, whereas the STRUCTURE analysis results had high support for three clusters.

CONCLUSIONS

The results obtained from this study provide important information on the genetic structures of the studied sainfoin genotypes and their genetic relationship. Therefore acquired genetic data will be useful in designing more efficient polycross nurseries, allowing open pollination of best performing and genetically diverse genotypes in the isolated conditions, which will increase genetic gain in sainfoin breeding programs.