Androgenic response of tomato (Lycopersicon esculentum Mill.) lines and their hybrids to anther culture.

摘要

The androgenic ability of four tomato (Lycopersicon esculentum Mill.) lines (Micro-Tina, Micro-Gemma, Moneymaker and MsK8 as parents) and their hybrids (obtained as half diallel crosses) were studied through anther culture, The isolated anthers were cultured on three culture media including M1 (Park et al., 2001), M2 (Summers, 1997) and M3 (Evans et al. 1986) exposed to two pretreatments (26+or-2 degrees C as a control and at 4 degrees C for 48 h as a cold pretreatment). Callus formation and callus growth (measured by callus diameter) occurred in the both pretreated anthers, but no callus produced shoot regeneration on the non-pretreated anthers. Statistical analysis showed significant differences between genotypes, culture media and their interactions for the studied traits. The highest callus formation was on M1 and M2 media, among which the longest callus diameter and the highest shoot regeneration were on M1 medium. The lines MsK8 and Micro-Gemma had a considerably higher frequency of callus formation and shoot regeneration and longer callus diameters than the other parents. On M1 medium, the highest frequency of callus formation and shoot regeneration belonged to hybrid MsK8 x Micro-Tina, and the longest callus diameter observed on hybrid Micro-Tina x Micro-Gemma. The mean values of callus formation, callus diameter, and shoot regeneration of hybrids in different culture media were significantly higher than those of the parents. In other words, heterosis (hybrid vigor) for the mentioned traits was observed on different culture media. Therefore, heterozygous genotypes (the hybrids) had a higher frequency of androgenic response than their parents.