Indexing Resilience to Heat and Drought Stress in the Wild Relatives of Rapeseed-Mustard.

Wild species are weedy relatives and progenitors of cultivated crops, usually maintained in their centres of origin. They are rich sources of diversity as they possess many agriculturally important traits. In this study, we analysed 25 wild species and 5 U triangle species of Brassica for their potential tolerance against heat and drought stress during germination and in order to examine the early seedling stage. We identified the germplasms based on the mean membership function value (MFV), which was calculated from the tolerance index of shoot length, root length, and biochemical analysis. The study revealed that B. napus (GSC-6) could withstand high temperatures and drought. Other genotypes that were tolerant to the impact of heat stress were B. tournefortii (RBT 2002), D. gomez-campoi, B. tournefortii (Rawa), L. sativum, and B. carinata (PC-6). C. sativa resisted drought but did not perform well when subjected to high temperatures. Tolerance to drought was observed in B. fruticulosa (Spain), B. tournefortii (RBT 2003), C. bursa-pastoris (late), D. muralis, C. abyssinica (EC694145), C. abyssinica (EC400058) and B. juncea (Pusa Jaikisan). This investigation contributes to germplasm characterization and the identification of the potential source of abiotic stress tolerance in the Brassica breeding programme. These identified genotypes can be potential sources for transferring the gene(s)/genomic regions that determine tolerance to the elite cultivars.

Genomic Selection: A Tool for Accelerating the Efficiency of Molecular Breeding for Development of Climate-Resilient Crops.

Since the inception of the theory and conceptual framework of genomic selection (GS), extensive research has been done on evaluating its efficiency for utilization in crop improvement. Though, the marker-assisted selection has proven its potential for improvement of qualitative traits controlled by one to few genes with large effects. Its role in improving quantitative traits controlled by several genes with small effects is limited. In this regard, GS that utilizes genomic-estimated breeding values of individuals obtained from genome-wide markers to choose candidates for the next breeding cycle is a powerful approach to improve quantitative traits. In the last two decades, GS has been widely adopted in animal breeding programs globally because of its potential to improve selection accuracy, minimize phenotyping, reduce cycle time, and increase genetic gains. In addition, given the promising initial evaluation outcomes of GS for the improvement of yield, biotic and abiotic stress tolerance, and quality in cereal crops like wheat, maize, and rice, prospects of integrating it in breeding crops are also being explored. Improved statistical models that leverage the genomic information to increase the prediction accuracies are critical for the effectiveness of GS-enabled breeding programs. Study on genetic architecture under drought and heat stress helps in developing production markers that can significantly accelerate the development of stress-resilient crop varieties through GS. This review focuses on the transition from traditional selection methods to GS, underlying statistical methods and tools used for this purpose, current status of GS studies in crop plants, and perspectives for its successful implementation in the development of climate-resilient crops.

Quality evaluation of near-isogenic line of the wheat variety HD2733 carrying the Lr24/Sr24 genomic region.

A near-isogenic line (NIL) of the Indian wheat variety HD2733, carrying an introgressed Lr24/Sr24 genomic region was used for studying the effect of this introgression on quality traits. Data on the grain yield and 21 quality traits were recorded in this NIL and its recurrent parent (RP), both of which were grown in a randomized block design for two consecutive years. The statistical analysis revealed that grain yield was on par between the NIL and the RP. The NIL and its RP were both hard grained but the NIL showed a grain hardness index reduced by 9.7%. However, quality traits such as grain weight, protein content, sedimentation value, gluten traits, and solvent retention capacity were significantly higher in the NIL. The NIL also showed an increase in dough stability, a lower degree of softening and a higher farinograph quality number. These results indicated that the NIL could be utilized for hard grain, high protein and strong gluten-based products. An overall improvement in the quality of the NIL over its recurrent parent and without any yield penalty suggests that the Lr24/Sr24 genomic region could be gainfully utilized in wheat breeding for improving the industrial quality of wheat without jeopardising grain yield. The authors suggest that the improved quality of the NIL may be due to the genomic segment carried along with the Lr24/Sr24 genes. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13205-021-02679-x.

Rheological evaluations and molecular marker analysis of cultivated bread wheat varieties of India.

The aim of this study was to screen Indian cultivated wheat varieties and list out the parameters/genes required to be improved for an end-product. Therefore, 30 Indian wheat varieties under cultivation by farmers were screened for 14 physico-chemical and rheological parameters, sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) for high molecular weight glutenin subunits (HMW-GS), DNA based molecular markers for low molecular weight glutenin subunits (LMW-GS) and puroindolines (Pin) genes. Based on grain texture, sedimentation value, farinographic, alveographic, HMW-GS and LMW-GS and biscuit making parameters, HS490 was found to be a highly suited for biscuit and soft wheat products. HI1563 and DBW14 were also found to possess characteristics such as low protein, low to medium SDS-sedimentation value and combination of 2*, 7+8 and 2+12 (HMW-GS). DBW14 also had LMW alleles desirable for biscuit quality. DBW14 needs to be improved for grain softness to make it suitable for biscuit quality while both grain softness and LMW alleles need to be improved for HI1563 to improve its biscuit spread factor and alveographic indices for extensible gluten. Rest varieties showed moderate to very strong gluten but the gluten lacked extensibility. Only four varieties K307, DBW39, NI5439 and DBW17 possessed high flour protein and moderately strong gluten. They had more balanced deformation energy (W) and configuration ratio (P/L) combination suggestive of strong and extensible gluten needed for raised bread making. Marker assisted backcross breeding is suggested as solution to produce end-use specific varieties where appropriate alleles at only a few loci need to be incorporated.

A Comparative Study of Single-Trait and Multi-Trait Genomic Selection.

In recent years of animal and plant breeding research, genomic selection (GS) became a choice for selection of appropriate candidate for breeding as it significantly contributes to enhance the genetic gain. Various studies related to GS have been carried out in the recent past. These studies were mostly confined to single trait. Although GS methods based on single trait have not performed very well in cases like pleiotropy, missing data and when the trait under study has low heritability. Gradually, some studies were carried out to explore the possibility of methods for GS based on multiple traits in the view of overcoming the above-mentioned problems in the method of single-trait GS (STGS). Currently, multi-trait-based GS methods are getting importance as it exploits the information of correlated structure among response. In this study, we have compared various methods related to STGS, such as stepwise regression, ridge regression, least absolute shrinkage and selection operator (LASSO), Bayesian, best linear unbiased prediction, and support vector machine, and multi-trait-based GS methods, such as multivariate regression with covariance estimation, conditional Gaussian graphical models, mixed model, and LASSO. In almost all cases, multi-trait-based methods are found to be more accurate. Based on the results of this study, it may be concluded that multi-trait-based methods have great potential to increase genetic gain as they utilize the correlation among the response variable as extra information, which contributes to estimate breeding value more precisely. This study is a comprehensive review of the methods of GS right from single trait to multiple traits and comparisons among these two classes.

Impact of treatment of gastrointestinal nemathelminths on body weight of sheep and goats.

Gastrointestinal nemathelminths affect productive as well as reproductive performance of a wide range of ruminants. To assess the impact of anthelmintic treatment on gain in body weight (b. wt.) of sheep and goat, a study was conducted using two different flocks of sheep and goats each maintained in semi intensive system. Infected animals in both the flocks were divided into three groups each. Group I and II in each flock were treated with levamisole (@7.5 mg/kg b. wt. subcutaneously) and fenbendazole (@5 mg/kg b. wt. orally), respectively. Animals of group III were kept as untreated control. Individual b. wt. and faecal egg count were recorded up to 42nd day post treatment. Results showed 100 % reduction in faecal egg count of sheep on day 7 after treatment with levamisole and on day 10 after treatment with fenbendazole. In goats, the reduction in faecal egg count was 82.60 % after treatment with levamisole and 78.87 % after treatment with fenbendazole on day 14 post treatment. The study also revealed mean increase of 29.57 and 22.67 % in b. wt. of sheep treated with levamisole and fenbendazole respectively 42nd day post treatment whereas mean b. wt. of infected untreated control groups decreased by 7.14 %. Similarly, there was an increase of 10.71 and 14.47 % in mean b. wt. of goats 42nd day post treatment with levamisole and fenbendazole, respectively whereas mean b. wt. of untreated control group decreased by 15.38 %. More weight gain was recorded in sheep as compare to goats after treatment as compared to the untreated control group, which may be due to some drug resistance in goat and required clarification by further studies in these ecological zones of Udham Singh Nagar.

Detection of benzimidazole resistance in gastrointestinal nematodes of sheep and goats of sub-Himalyan region of northern India using different tests.

The present investigation was planned with the objective of studying the status of benzimidazole (BZ) resistance in gastrointestinal nematodes (GIN) of sheep and goats of different agro-climatic zones of sub-Himalyan region of northern India using in vivo faecal egg count reduction test (FECRT) and in vitro tests namely egg hatch assay (EHA) and larval development assay (LDA). Out of fourteen flocks, FECRT detected resistance in eight flocks (two sheep flocks and six goat flocks) with FECR% ranging from 54.95 to 90.86. Pre treatment coproculture contained predominantly Haemonchus contortus, followed by Trichostrongylus spp., Oesophagostomum and Strongyloides, while post treatment coproculture results showed that only H. contortus survived fenbendazole (FBZ) (in FECRT) or thiabendazole (TBZ) (in LDA) treatment except in three flocks of Tarai region {one sheep flock (Us1), and two goat flocks (Ug1 and Ug5)} where BZ resistant Trichostrongylus were also detected. The GIN of those eight farms which were found resistant by FECRT were also detected resistant by EHA. Arithmetic mean and range of ED50 value of susceptible group was found to be 0.059 µg/ml and 0.037-0.096 µg/ml, respectively, and the same for the resistant group were found to be 0.119 µg/ml and 0.101-0.147 µg/ml, respectively. With LDA, the arithmetic mean and range of LC50 value of susceptible group was found 0.0030 µg/ml and 0.001-0.005 µg/ml, respectively, and those of resistant group was found 0.0105 µg/ml and 0.009-0.012 µg/ml, respectively. The values of Spearman rank correlation coefficient indicated that negative correlation was found between FECR% and ED50 and between FECR% and LC50 while positive correlation existed between ED50 and LC50 value and the p-values indicated that these correlations were statistically highly significant. In the present study, FECRT and EHA gave comparable results with regard to detection of BZ resistance in GIN in sheep and goats. Although with LDA, the threshold LC50 value could not be established as for EHA but LDA indicated the presence of low level of resistance in GIN of both sheep and goats. For effective worm control, regular monitoring for anthelmintic resistance is important to know the status of anthelmintic efficacy in a particular agro-climatic zone. The baseline information thus generated will enable timely management of benzimidazoles resistance in GIN.