Unveiling of suppressed genes in interspecific and backcross populations derived from mutants of Cicer species

Abstract

Although many interspecific crosses in Cicer species have successfully been carried out to improve the population in cultivated chickpea (Cicer arietinum L.), interspecific and backcross populations derived from mutants of Cicer species have not been studied for revealing suppressed genes responsible for heterotic effects and transgressive segregations. Therefore, the study aimed (i) to estimate heterosis (here, offspring superior to mid-parent value) and heterobeltiosis (offspring superior to better parent) for yield and yield components in the F1; (ii) to decipher transgressive segregation (extreme phenotypes) in F2 and backcross populations; and (iii) to reveal suppressed genes in interspecific and backcross populations (C. arietinum × F1 and C. reticulatum Ladiz.× F1) derived from interspecific crosses between a mutant of C. arietinum and a mutant of C. reticulatum. Heterobeltiosis was found for seed and biological yields, number of branches, and number of pods per plant in F1 progeny; heterosis was determined for the additional traits of 100-seed weight and harvest index. Heterobeltiosis and heterosis for yield and yield components in F1 progeny prompted transgressive segregation for these traits in F2 and backcross populations. In the backcrosses, C. arietinum × F1 crosses produced greater seed size and more pods per plant than C. reticulatum × F1, suggesting that C. arietinum × F1 backcrossing could improve yield components and lead to large seed size. Most of the high-yielding progeny in F2 and C. arietinum × F1 populations had double-podded nodes. It was concluded that the suppressed genes in a mutant of C. reticulatum or a mutant of C. arietinum played a crucial role in increasing transgressive segregations and allowing the cultivated chickpea to gain increased yield and yield components as well as large seed size.