濒危植物金花茶开花物候和生殖构件特征

The Flowering Phenology and Characteristics of Reproductive Modules of Endangered Plant Camellia nitidissima

摘要:

对桂林雁山迁地保护的金花茶(Camellia nitidissima)开花物候和生殖构件特征进行了研究。结果表明：(1)单花开放过程可分为蕾松、初开、盛开、落花4个阶段，单花寿命约2~8 d；(2)个体花期长，始花时间变异大，单株花期平均为37 d，始花时间可相差2个多月，种群始花时间为1月上旬，3月上旬达到开花高峰期，花期持续近3个月；(3)生殖构件的数量与个体径级和树冠层次有一定关系，地径大于6 cm的个体，其单株花数、生殖枝数、生殖枝比率显著高于地径小于4 cm和4~6 cm个体，而每生殖枝花数则无显著差异；不同树冠层次之间，平均生殖枝数和生殖枝比率，以中、下层显著高于上层，而每生殖枝花数以上层最高，花数在不同冠层之间无显著差异；(4)花芽期败育率为16.33％，花期败育率为63.05％，果期败育率为44.09％，败育率在不同径级个体和不同冠层之间有一定差异；败育率高，结实率低，种子产量少，是金花茶濒危的一个主要原因；(5)开花数目与花期长度呈正相关，个体始花时间与花期长度、座果率之间存在显著的负相关关系。

Abstract:

Camellia nitidissima is one of endangered plants in China. Its flowering phenology and reproductive modules features of ex situ conservation in Guilin were investigated. The results showed that flowering process could be divided into four stages, such as loosing, opening, blooming and falling. The single flower life ranged from 2 to 8 days. The average blooming period of individuals was 37 days. The initial time of flowering in individuals showed great variability about more than two months. The initial time of flowering in population was in early January, and reached peak at early March, its blooming period lasted nearly 3 months. The number of reproductive modules related to plant diameter class and the layer of crown. The number of flowers and reproductive branches, ratio of reproductive branch of plant diameter > 6 cm were significantly higher than those of plant diameter < 4 cm and 4~6 cm, but no significant difference in flower number per reproductive branch. In different crown layers, the middle and lower layer were significantly higher than upper layer in number of reproductive branches and reproductive branch ratio, however, flower number per reproductive branch in upper layer was the biggest, and the number of flowers showed no significant difference. The abortive rate at bud stage, flowering stage, fruit stage were 16.33%, 63.05% and 44.09%, respectively, and they were differences among different plant diameter classes and crown layers. The high abortive rate lead to low setting and seed yield, it is one of reasons to make C. nitidissima endangered. Number of flowers was positively correlated with blooming period and initial time of flower was negatively correlated with blooming period and fruit setting.