An analysis of polygenic variation in the M4 families of coriander (Coriandrum sativum L.)

Abstract

Mutation breeding programme has been undertaken with selective mutagen doses (Sodium azide, 1mM; Hydroxylamine 1% and Gamma rays 10, -25kR doses) in coriander (Corianderum sativum L.), an important spice crop of the country (1). The objective was to develop improved varieties, 'which is rather lacking in this crop due to narrow range of genetic variability and susceptibility to biotic and abiotic stresses (2 and 4). This investigation reports on the polygenic variation noted in M4 progenies of three coriander varieties for yield and yield attributes. The M4 progenies of the three varieties were developed through inter mating 6-10 plants both in M2 and M3 generations by covering them with muslin cloth bag during flowering. The intermating was done to avoid poor seed setting that might result from inbreeding depression where single plant is selfed. Each M2 progeny, however, was corresponded to single M1 plant which was selfed and only those M2 progenies which had significantly higher yield than their respective controls (Parents) were advanced to M4 generation without evaluating their M3 generation. There were 63 M4 progenies of coriander variety RCr-41, 64 of RCr-436 and 23 of RCr-20 included in the present investigation. For progenies of each variety, we expected a variation attributable to the difference between the means of the M4 progenies, difference between different individuals of progenies, new recombinants resulting from their intermating and expression of the mutated genes. The variance analysis (5) revealed that between progeny component of variance was significant for all the characters studied in the M4 progenies of the three varieties, thus substantiating our expectation.