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In this study, the resistance of selected canola genotypes to the mustard aphid Lipaphis erysimi (Kaltenbach) was investigated. Molecular characterization of plant resistance was conducted, and genetic variability was observed between the resistant (KS-75) and susceptible (Abaseen) genotypes of brassica. Three RAPD markers were identified that were associated with the resistance. This study was conducted to compare the genetic data between two genotypes (KS-75 resistant and Abaseen susceptible), with an average of 4.3 bands per primer. The amplification bands per primer ranged from 9 to polymorphic fragments of 8, with fragment sizes ranging from 450 to 1700 base pairs to 9 kilo base pairs (kbps). Amplification of the largest fragment in 9 kbps using four primers (A 1–12, B 1–12, K 1–12 and L 1–12) resulted in a mean 92 percent identity index between the first two resistant and susceptible genotypes. KS-75 resistant had the highest mean genetic diversity of 92 percent, while Abaseen susceptible had the lowest mean genetic diversity of 8 percent. Out of the three markers tested, two were found to be positively associated with aphid resistance, while one was negatively correlated. These markers can be used to help develop a pre-emptive strategy for aphid resistance in brassica species, without having to simultaneously select for yield and quality related traits.

In this study, the resistance of selected canola genotypes to the mustard aphid Lipaphis erysimi (Kaltenbach) was investigated. Molecular characterization of plant resistance was conducted, and genetic variability was observed between the resistant (KS-75) and susceptible (Abaseen) genotypes of brassica. Three RAPD markers were identified that were associated with the resistance. This study was conducted to compare the genetic data between two genotypes (KS-75 resistant and Abaseen susceptible), with an average of 4.3 bands per primer. The amplification bands per primer ranged from 9 to polymorphic fragments of 8, with fragment sizes ranging from 450 to 1700 base pairs to 9 kilo base pairs (kbps). Amplification of the largest fragment in 9 kbps using four primers (A 1–12, B 1–12, K 1–12 and L 1–12) resulted in a mean 92 percent identity index between the first two resistant and susceptible genotypes. KS-75 resistant had the highest mean genetic diversity of 92 percent, while Abaseen susceptible had the lowest mean genetic diversity of 8 percent. Out of the three markers tested, two were found to be positively associated with aphid resistance, while one was negatively correlated. These markers can be used to help develop a pre-emptive strategy for aphid resistance in brassica species, without having to simultaneously select for yield and quality related traits. [ABSTRACT FROM AUTHOR]

The study on categories of resistance in selected canola genotypes against mustard aphid (Lipaphis erysimi) was conducted under glasshouse conditions, The University of Agriculture, Peshawar during growing seasons of 2018-2019. During this study, a total of two different experiments were carried out where, antixenosis experiment, comprised three levels; seedling, flowering and pod stage. In all the three stages, only genotype 'KS-75' proved as antixenosis resistant against the aphid compared to susceptible genotype Abaseen. The second experiment was performed to test antibiosis resistance against L. erysimi among the selected genotypes. During the antibiosis experiment different life table parameters of aphids; developmental period, reproductive period, longevity and fecundity were studied. Based on the calculations, only 'KS-75' proved antibiosis resistant against L. erysimi among the selected genotypes. Thus, during our current studies, genotype KS-75 proved antixenosis and antibiosis characteristics based on less number of aphids attracted/sustained and low number of progenies produced as compared to the tested genotypes Abaseen, Omega and Zahoor showed strong vigor against mustard aphid and symptoms of attack/damages were observed. [ABSTRACT FROM AUTHOR]