Agronomic evaluation for phenotypic stability of cytoplasmic male sterile lines in rice (Oryza sativa L.)

Abstract

Phenotypic stability in respect of important agronomic traits influencing hybrid seed yield in the cytoplasmic male sterile (cms) lines is highly desirable over a range of sowing dates to ensure commercially feasible and economically viable hybrid seed production. Among the large number of cms lines developed over the years, only few possess traits suitable for developing commercial hybrids. Keeping this in view, ten cms lines were performance-tested for six agronomic traits across four dates of sowing. The cms lines (Table 1) were evaluated in randomized complete block design in four environments created by varying the date of sowing (E1 - 1st June, E2 - 10th June, E3 - 20th June and E4 - 30th June) at the Indian Agricultural Research Institute, New Delhi. Thirty days old seedlings were transplanted in the main field. Each entry was allotted to three rows plot keeping 20 cm and 15 cm distance between rows and between plants within the rows, respectively. All recommended agronomic practices were followed. The observations were recorded on five randomly chosen plants per plot for plant height (cm), number of tillers per plant, panicle length (cm), number of spikelets per panicle, number of primary branches per panicle and panicle exsertion (%). The data were analysed statistically for stability parameters following Eberhart and Russell [1] model. The significance of deviation of regression coefficient from unity was tested by t-test.