MULTIVARIATE ANALYSIS AND EVALUATION OF HYBRIDS WITH THEIR PARENTS IN FINE RICE

Abstract

Twenty five fine rice genotypes including thirteen non-aromatic and twelve aromatic cultivars were evaluated for fifteen quantitative characters to select the most yield enhancing characters as well as the diverged cultivars for hybridization. The mean performances and genetic parameters of the characters were separated through univariate analysis; the most yield promoting characters were selected by bivariate and multivariate analyses and desirable parents were selected by univariate and multivariate analyses. Though high heritability was estimated for most the characters but the highest genetic advance was estimated against spikelets/panicle (125.74). Effective tillers/hill, spikelets/panicle showed positive and significant, and plant height, days to 50% flowering and days to maturity showed negative and significant correlation coefficients with yield. Upon partitioning the total phenotypic correlation coefficients with yield, 1000-grain weight exerted the highest direct effect (0.84), followed by spikelets/panicle (0.67) and effective tillers/hill (0.61), therefore, these three characters appeared as the predominant yield accelerating characters in fine rice. A total of thirty selection indices were constructed based on five characters including yield and the highest relative efficiency of simultaneous selection was gained from I12345 (223.31%). Twenty five cultivars were grouped into six clusters by D2 statistics and six cultivars such as Kataribhog, Salna, Ranjit, Begunbichi, Chinigura and Kalozira were selected based on clustering as well as rank distribution of the cultivars. The selected parental lines were evaluated both in research and farmer’s fields to assess their tangible performance for the selected characters. The estimated yield gap between the research and the farmer’s fields was 0.86 t/ha. The selected cultivars produced significantly higher effective tillers/hill, spikelets/panicle and yield in the research field than that of farmer’s field. However, the potentiality of the segregants was predicted in the course of such comparison. It was initially aimed to develop fifteen experimental hybrids through a diallel model, but eight hybrids were finally produced from these six parental lines. The cytogenetical barrier against the failure of seven hybrids was investigated. The non remarkable karyotypic disharmony in the parents may not be the principal cause behind the failure of seven hybrids; other reasons like genetical, physiological and environmental factors may be responsible to create such partial hybridization failure that need to be further investigation. The eight hybrids were evaluated and their competence was measured by three criteria of heterosis. The aroma contents in the hybrids and their parents were compared. Out of eight hybrids, three were non-aromatic and five were aromatic, in which the highest aroma was assessed in the F1 of Kataribhog × Salna and F1 of Kataribhog × Chinigura, hence consideration of yield and aroma content these two hybrids may bring to obtain desirable segregants.