Search

In wheat (Triticum aestivum), canopy architecture, culm diameter and stem strength are the key providers of lodging tolerance. To better understand the lodging phenomenon and determine the best linked trait to lodging, a study of lodging resistance was conducted in both artificially-induced and natural lodging conditions. Various morphological, phenological and biochemical traits, such as acid detergent fibre, acid detergent lignin, cellulose and activity of lignin-synthesising enzymes (phenylalanine ammonia lyase and tyrosine ammonia lyase) were recorded. Anatomical features were also examined by light microscopy, using the Wiesner reaction. Genotype C306 demonstrated the highest susceptibility to lodging compared to other varieties due to its limited production of lignin-synthesising enzymes, as well as its taller plant height and narrower culms. The dwarf mutants (DM6 and DM7) have a stronger resistance against lodging because they have thick stems and a short plant canopy structure. The most suitable donors for lodging are semidwarf varieties (HD2967, DPW621-50, DBW88) because they have higher production of lignin and lignin-synthesising enzymes. Grey correlation analysis also confirmed the ability of these three genotypes to tolerate lodging. The genotypes studied were comprehensively ranked. The study also includes an effort towards the standardisation of lodging methodology under artificial conditions. Lodging occurs when crop stems bend permanently from their usual upright position, reducing yield. Lodging has been witnessed in various places worldwide, and its unpredictable nature makes it a substantial constraint for yield improvement.To better understand this process and determine the trait best correlated with lodging in wheat (Triticum aestivum), a study was conducted under both artificially-induced and natural lodging conditions. Genotypes were ranked, and we tried to standardise methodology for measuring lodging tolerance in an artificial environment. [ABSTRACT FROM AUTHOR]

The study was conducted to identify novel simple sequence repeat (SSR) markers associated with resistance to corn aphid (CLA), Rhopalosiphum maidis L. in 48 selected bread wheat (Triticum aestivum L.) and wild wheat (Aegilops spp. & T. dicoccoides) genotypes during two consecutive cropping seasons (2018–19 and 2019–20). A total of 51 polymorphic markers containing 143 alleles were used for the analysis. The frequency of the major allele ranged from 0.552 (Xgwm113) to 0.938 (Xcfd45, Xgwm194 and Xgwm526), with a mean of 0.731. Gene diversity ranged from 0.116 (Xgwm526) to 0.489 (Xgwm113), with a mean of 0.354. The polymorphic information content (PIC) value for the SSR markers ranged from 0.107 (Xgwm526) to 0.370 (Xgwm113) with a mean of 0.282. The results of the STRUCTURE analysis revealed the presence of four main subgroups in the populations. Analysis of molecular variance (AMOVA) showed that the between-group difference was around 37 per cent of the total variation contributed to the diversity by the whole germplasm, while 63 per cent of the variation was attributed between individuals within the group. A general linear model (GLM) was used to identify marker-trait associations, which detected a total of 23 and 27 significant new marker-trait associations (MTAs) at the p < 0.01 significance level during the 2018–19 and 2019–20 crop seasons, respectively. The findings of this study have important implications for the identification of molecular markers associated with CLA resistance. These markers can increase the accuracy and efficiency of aphid-resistant germplasm selection, ultimately facilitating the transfer of resistance traits to desirable wheat genotypes. [ABSTRACT FROM AUTHOR]