Central Soil & Water Conservation Research & Training Institute, Research Centre, Bellary, 583104, India
1Present address: 145, Railway Lines, Solapur, 413001.
The nature and magnitude of heterosis for plant yield, seed oil percent and a number of other variables related to fitness and productivity in cultivated safflower were assessed in the F1 generation of 8 x 8 full diallel in 1978 and 10 x 10 in 1979. Hybrids displayed substantial differences in their heterotic responses for various characters. Averaged over 146 crosses from both the diallels, heterosis was very high for yield per plant (55%), high for capitulum weight (26%), moderate for capitula number (19.5%) and number of primary branches/plant (13.5%), low for capitulum diameter (6 8%) and negligible or absent for plant height, flowering time, seed weight and percent oil. Hybrids outyielded their superior parents in 76 cases and the best adapted check in 28 cases out of 146 examined. The highest yielding hybrid in the material excelled its superior parent by 119% and the bast standard check by 70% across reciprocal crosses. Hybrids between genetically diverse parents manifested more hybrid vigour than those from closely related ones. A number of top yielding crosses involved either one or both the parents otherwise low or medocire in yield potential. Ranking of crosses based on their heterotic effects over mid or superior parents showed relatively poor agreement with the actual per se performance of crosses. Heterosis for yield in the material was mostly associated with hybrid vigour in number and/or weight of capitula. Reciprocal differences were, in general, low or absent in safflower. No undesirable heterotic responses in maturity duration, plant height and oil percent were detected in crosses that manifested significant positive heterosis for yields. The results suggest tremendous potential of hybrids in safflower for raising per hectare yields and oil out-turn
