| Summary, etc. |
Rice bean (Vigna umbellata (Thunb.) Ohwi and Ohashi) is a native crop of South and South East Asia. Rice bean has been gaining importance as supplementary non-traditional tropical pulse crop due to its resistance to yellow mosaic virus, brucids, high grain yield, better nutritional value and multiple usages as food, feed, cover-crop, green manure and soil enricher. Being a relatively new introduction as a crop, not much work on breeding and selection for yield improvement has been reported. Therefore, the present investigation was conducted to identify morphological components contributing to seed yield and an ideal plant type to suggest the direction and magnitude of selection that would accrue most yield advantage under selection. The materials consisted of 79 genotypes of rice bean, including RBL-6 of rice bean and mung bean variety , Asha ' as checks. The experiment was sown in a randomized block design (RBD) with three replications in experimental area, Department of Plant Breeding, Hisar during kharif 2000. Genotypes were sown in a single row of 1.5 meter length with inter-row and interplant spacing of 100 and 15 centimeters, respectively. The mean data recorded for different morphological characters, yield para- meters and seed yield per plant were used to com- pute correlation coefficients at phenotypic and ge- notypic levels according to Al-Jibouri et al., (1958). Phenotypic and genotypic correlation coeffi- cients for different parameters have been presen- ted in the Tab1e 1. The magnitude of the genotypic correlation coefficients was higher than that of phenotypic correlation coefficients, indicating lesser interference of the environment. The results of inter-relationship between seed yield and various morphological characters are described below: Days to flower (DF): It had positive and highly significant correlation coefficients with days to ma- turity plant height, pod length and test weight, whereas it was negatively and highly significantly associated with clusters per plant, pods per cluster, pods per plant, seeds per pod and seed yield per plant. This indicated that early flowering affect the seed yield and its parameters positively towards increasing seed yield. Days to maturity (DM): It had positive and highly significant to significant correlation coeffici- ents with days to flower, plant height, pod length and test weight. It was negatively associated with clusters per plant, pods per cluster, pods per plant, seeds per pod and seed yield per plant, indicating that early maturity is desirable]e for increasing seed yield. Plant height (PH): It was positively and significantly associated with days to flower, days to maturity, pod length and test weight, while it was negatively and significant associated with clusters per plant, pods per cluster, pods per plant, seeds per pod and seed yield per plant. This revealed the desirability of short statured genotypes which are non-climbers or determinate types. Clusters per p]ant (C/P): It was found to be positively and highly significant]y associated with pods per cluster, pods per p]ant, seeds per pod and seed yield per plant, revealing their importance in enhanced seed yield. On the other hand, it had negative and high]y significant associations with days to flower, days to maturity, plant height, pod length and test weight. Pods per cluster (P/C): It was found to be positively and significantly correlated with clusters per plant, pods per plant, seeds per pod, and seed yield per plant. On the contrary, it was negatively and significant]y associated with days to flowering, days to maturity, plant height, pod length and test weight. Pods per plant (P/P): It exhibited positive and significant correlation coefficients with clusters per plant, pods per cluster, seeds per pod and seed yield per plant. On the other hand, it expressed negative and significant correlations with days to flower, days to maturity, plant height, pod length and test weight. Pod length (PL): It showed positive and significant correlations with days to flower, days to maturity, plant height and test weight, whereas it exhibited negative and significant correlations with clusters per plant, pods per cluster, pods per plant and seed yield per plant, exhibiting undesirability of long pods. Seeds per pod (S/P): It was found to be positively and significantly associated with clusters per plant, pods per cluster, pods per plant and seed yield per plant, revealing its desirability. Contrarily, it was negatively and significantly associated with days to flower, days to maturity, plant height and test weight. Test weight (TW): It had positive and significant correlation coefficients with days to flower, days to maturity, plant height and pod length, while it was negatively and significantly correlated with clusters per plant, pods per cluster, pods per plant, seeds per pod and seed yield per plant, indicating the desirability of small seeded genotypes. Seed yield per plant (SY /P): It was found to be positively and significantly associated with dif- ferent component characters viz., clusters per plant, pods per cluster, pods per plant and seeds per pod (Kumar et al., 1997 and Chaudhari et al., 2000). However, seed yield per plant was negatively and significantly associated with days to flower (Sarma et al., 1991), days to maturity (Arya and Singh, 1994 ), plant height, pod length and test weight. On the basis of above results, it can be con- cluded that an ideal plant should be early flowering, early maturity, short statured (determinate/non- climbers ), small pod length and low test weight along with high clusters per plant, pods per cluster, pods per plant and seeds per plant, for the enhancement of he seed yield. |