This research work was performed at Nuclear Institute for Agriculture and Biology (NIAB) Faisalabad Pakistan and castor mutants under study were obtained after treating three castor varieties viz. DS 30, C 176 and DC 15 with gamma rays ranging from 100-500 Grey during Kharif 2003. The selection was performed in M2 generation and confirmation of characters in the subsequent generations. Vigorous selections remained in progress during each succeeding generation for desirable yield and yield components. Then afterward these elite selected mutant lines were evaluated from 2007 to 2010 in randomized complete block design (RCBD) in three repeats. Combined analysis of variance indicated that genotypes (A), environment (B) and interaction between A x B was highly significant. Overall mean performance of castor mutants showed significant differences with maximum seed yield (2776 kg ha-1 ) estimated in mutant M 7-35-12-1 and minimum in standard check DS 30 (1825 kg ha-1 ). M 7-35-12-1 produced 52.10% higher seed yield followed by L 57-32-784 (39.78%) and M 7-35-1-2 (35.34%). Regarding regression coefficient (b), mutant line L 36-24-124 was more near to unity followed by M 7-35-12-1. Standard check DS 30 not only produced poorest seed yield but had very less regression coefficient value (0.585) which indicated that variety is most suited to special type of environment. The maximum value of regression coefficient was estimated in mutant DC 1525421 (b=1.299) which showed that the line is most suited for rich environment. Standard deviations to regression (Sd2 ) values were not higher and less than unity and ranged from 0.107 to 0.390. Mutant line M 7-35-12-1 had minimum value and standard check DS 30 with highest value. Moreover, mutant line M 7-35-12-1 had less maturity period (125 days) as compared to 200 days of DS30 and it can easily be harvested in one cutting operation before cultivation of wheat and can be best fitted in wheat-castor rotation. Development of this early mutant has created the chances of adaptation of economically potential castor as major a crop that will contribute in meeting the increasing demands of castor oil.
G. Sarwar, M. Hassan, M.B. Chaudhry, S.S. Alam. (2013) GENOTYPIC X ENVIRONMENT INTERACTION OF CASTORBEAN GROWN OVER MULTIPLE YEARS , , Volume 10, Issue 2.
