红心柚‘橘湘红’无核原因初探

以红心柚‘橘湘红’为材料,安江香柚为对照,通过物候期和花器特征的观察、花粉活力的测定、自交和异交花粉管在柱头中的生长及果实种子差异分析,探讨‘橘湘红’无核的原因。结果表明:‘橘湘红’的物候期与对照仅相差2~3 d,花器发育均正常;‘橘湘红’、安江香柚花粉在柱头上的萌发率分别为98.81%、97.96%,花粉活力分别为96.75%、94.61%,可育性高;自交与异交授粉96 h后,花粉管生长开始出现差异,自交花粉管生长速度减缓,异交花粉管生长正常,授粉120 h后,自交的花粉管停滞生长,异交的花粉管生长到达花柱基部;‘橘湘红’异花授粉平均每个果实有正常种子103.8粒,自花授粉果实无正常发育的种子。综合分析认为自交不亲和性可能是‘橘湘红’无核的主要原因。

Preliminary investigation on the seedless red pulp pomelo of 'Juxianghong'

The seedless red pulp pomelo of 'Juxianghong' was used as material and Anjiangxiangyou as control, to study the reason of seedlessness of 'Juxianghong' by observing the phenophase and floral characters, measuring the pollen activity and analyzing the variance of the growth of pollen tube of self-pollinationself and cross-pollination in the stigma with fruit seeds. The results showed that the phenophase of 'Juxianghong' was similar to the Anjiangxiangyou and was only two to three days difference; the developments of their floral organ were normal; the pollen germination rates of 'Juxianghong' and Anjiangxiangyou in stigma were 98.81% and 97.96% and their pollens had high activities (96.75% and 94.61%) and high fertility; the growth of pollen tube with cross-pollination was normal and reached the base of style after 120 h of pollination, while the growth of pollen tube with self-pollination began to decrease at 96 h and stopped at 120 h after pollination; there were no normal seeds in the fruits by self-pollination, while 103.8 normal seeds were found in the fruits by cross-pollination. Comprehensive analysis shows that self-incompatibility might be the main reason for the seedlessness of 'Juxianghong' pumelo.