HYBRIDIZATION IN SIDA-OVATA COMPLEX .2. EVIDENCE FROM BREEDING STUDIES

Breeding studies reconfirmed the hybridization between Sida ovata Fors sk., and Sida tiagii Bhandari. All the three taxa i.e., S. ovata Forss k., S. tiagii Bhandari and the hybrid are facultative autogamous as in dicated by pollen - ovule ratios and breeding experiments. Chrysis sp. , (Hymenoptera) seems to be responsible for pollen transfer between S. ovata and S. tiagii in natural populations. Certain insect pollinator s were specific such as Bembix sp., and Bombus sp., for S. ovata, Apis sp., and Vespa sp., for S. tiagii and Ponera sp., for the hybrid. The limited number of hybrids may be due to less frequent visitation of c ommon pollinator (Chrysis sp.) alongwith the incomplete reproductive b arrier between both the parents. The restricted gene now is also evide nt by least fruit and seed set in hand pollinated reciprocal crosses o f the putative parents as compared to the self pollination. It seems t hat back crosses are impeded due to the absence of common pollinators between the parents and hybrid and meiotic irregularities as indicated by the failure of hand pollinated (back crosses) experiments.