بررسي الگوهاي خودناسازگاري براي شناسايي رقم‌ هاي خودسازگار و خودناسازگار اطلسي (Solanaceae) Petunia hybrida grandiflora

A study the patterns of self-incompatibility for discrimination of self-compatible and self-incompatible cultivars of Petunia hybrida grandiflora (Solanaceae)

Self-incompatibility is one of the most important mechanisms by which plants prevent inbreeding. In this investigation, the pollen tube growth of eight cultivars of Petunia hybrida grandiflora was studied in vitro and in vivo in pistils which were both self-pollinated and in pistils which were cross-pollinated. In addition, the amount of seed set in inbreeding and out-breeding flowers was investigated as the index of self-incompatibility. Using these results, self-compatible and selfincompatible cultivars were discriminated. After 48 hours of self- and cross pollination, the pollen tube growth was studied by fluorescent microscopy in vivo. The results in all cultivars showed normal growth of pollen tubes on culture medium. Fluorescent microscopy studies showed normal germination and growth of pollen tubes on stigmas. In style, the abnormalities of pollen tube growth were observed in self-pollinated. pistils of some cultivars. Some of these abnormalities include pollen tube growth inhibition in 1/3 upper part of the style, and. variable pollen tube diameter in middle and lower part of the style. Seed set studies showed a significant decrease in seed set of self-pollinated pistils as compared with cross-pollinated pistils. In our study, the cultivars containing these abnormalities as well as those with decreased seed set were defined as selfincompatible. Thus, we could be able to discriminate self-compatible cultivars from self-incompatible ones by these characters.