梵净山尖连蕊茶花粉育性与形态比较研究

Comparative study on pollen fertility and morphology of Camellia cuspidata in Fanjing Mountain

关键词:  尖连蕊茶, 花粉数量, 花粉活力, 花粉形态, 聚类分析

Key words:  Camellia cuspidata, pollen number, pollen viability, pollen morphology, cluster analysis

摘要:

为了探究梵净山的尖连蕊茶不同优株花粉育性与形态特征差异,以及为其杂交育种提供参考,该研究以不同种质的9个尖连蕊茶优株为材料,通过纤维素酶分解法测定花粉数量,采用琼脂离体萌发培养法测定花粉活力,运用扫描电子显微(SEM)镜观察其花粉的形态特征并基于极轴长(P)、赤道轴长(E)、萌发沟长(L)、P/E值、P × E值及L/P值等数量指标进行聚类分析。结果表明:(1)梵净山尖连蕊茶的花粉数量和花粉活力均较高。单粒花药花粉数量变化范围为4 780～12 950粒; 除FJSCF9花粉萌发率只有71.43%以外,其余优株均高于91.20%。(2)尖连蕊茶花粉的外壁纹饰包括穴状、网状、脑纹状、皱波-颗粒状、皱网状、皱波状6种纹饰类型。9个种质尖连蕊茶花粉的形态特征差异明显:其花粉粒大小(P × E值)变化范围为1 903～2 275.92 μm²,花粉L/P值变化范围为0.79～0.89; FJSCF3极轴长显著高于其他种质(P<0.05),为64.20 μm,然而FJSCF12萌发沟长显著低于其他种质(P<0.05),为43.77 μm。(3)聚类分析显示9个种质尖连蕊茶可分为3类:第Ⅰ类群包含FJSCF1、FJSCF4、FJSCF8、FJSCF9、FJSCF10、FJSCF11共6份材料,花粉中等大小; 第Ⅱ类群包含FJSCF12和FJSCF13共2份材料,花粉较小; 第Ⅲ类群仅FJSCF3 1份材料,花粉粒大,P值和P × E值最大,分别为64.20 μm、2 275.92 μm²。综上认为,该研究中来自梵净山的9个种质尖连蕊茶具有较高的花粉育性,可作为杂交育种父本材料,其花粉粒形态特征和花粉粒表面纹饰可作为种内分类辅助参考指标。

Abstract:

This study aimed to investigate the variations in pollen fertility and morphological characteristics among different provenances of Camellia cuspidata from Fanjing Mountain, thereby providing insights for parental selection in hybrid breeding. Nine superior variety individuals of C. cuspidata from different provenances were used as experimental materials. Pollen number was determined using a cellulase decomposition method, pollen viability was assessed through in vitro agar germination assays, and pollen morphological features were observed via scanning electron microscopy(SEM). Cluster analysis was conducted based on the following quantitative traits: polar axis length(P), equatorial axis diameter(E), sulcus length(L), P/E value, P × E value, and L/P value. The results were as follows:(1)C. cuspidata from Fanjing Mountain exhibited high pollen productivity and viability. The number of pollen grains per anther ranged from 4 780 to 12 950. Pollen germination rate exceeded 91.20% in all genotypes except for FJSCF9, which showed a germination rate of 71.43%.(2)The exine ornamentation of C. cuspidata pollen included six distinct types: foveolate, reticulate, cerebroid, rugulate-granular, rugulate-reticulate, and rugulate. Considerable morphological variation was observed among the nine provenances. Pollen size(P × E value)ranged from 1 903 to 2 275.92 μm², and the pollen L/P values between 0.79 and 0.89. The polar axis length of FJSCF3(64.20 μm)was significantly greater than those of other provenances(P<0.05), while the sulcus length of FJSCF12(43.77 μm)was significantly shorter than those of other provenances(P<0.05).(3)Cluster analysis classified the nine provenances into three groups: Group I comprised six accessions(FJSCF1, FJSCF4, FJSCF8, FJSCF9, FJSCF10, and FJSCF11), characterized by medium-sized pollen; Group Ⅱ included two accessions(FJSCF12 and FJSCF13)with relatively small pollen; Group Ⅲ consisted solely of FJSCF3, which had the largest pollen grains, along with the greatest P and P × E values(64.20 μm and 2 275.92 μm², respectively). In conclusion, the nine provenances of C. cuspidata from Fanjing Mountain demonstrated high pollen fertility, suggesting their potential use as paternal parents in hybridization breeding. Additionally, pollen morphology and exine sculpturing patterns can serve as auxiliary indicators for intraspecific classification and identification.