Pollen Tube Growth and Double Fertilization in Camellia oleifera
Pollen Tube Growth and Double Fertilization in Camellia oleifera
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DOI：
10.21273/jashs.140.1.12
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发表时间：
2015-01-01
影响因子：
1.9
通讯作者：
Zou, Feng
中科院分区：
文献类型：
--
作者：
Gao, Chao;Yuan, Deyi;Zou, Feng
油茶是一种重要的食用植物。了解这种植物的双受精作用对于研究杂交育种、自交不亲和性和杂交的生物学机制至关重要。我们的目的是表征花粉管生长和双受精在C。油橄榄以花烁和湘林XLC 15为母本和父本进行人工授粉。利用荧光显微镜和扫描电镜观察了授粉至受精过程中花粉管在花柱、子房和胚珠中的生长情况以及双受精过程中雌、雄配子融合的细胞学特征。授粉后2 ~ 4小时大量花粉萌发。花粉管进入乳突细胞间隙，沿花柱道沿着生长，在花柱1/3处聚集。它们生长在逐渐变窄的花柱沟中，进入子房室。这些管旋转90度，通过珠孔进入胚囊;随后，它们进入退化的助细胞，在那里释放精子细胞。一个精核与极核融合，形成初生胚乳核，而另一个精核与卵融合，形成合子。极核受精早于卵。双受精C. oleifera的特征是有丝分裂前配子生殖。本研究结果为进一步开展红腹锦鸡儿的杂交育种和胚胎学研究奠定了理论基础。为山茶属植物的生殖生物学研究提供了基础资料。
Camellia oleifera is an important plant species that produces edible oils. Understanding the double fertilization of this plant is critical for studies concerning crossbreeding, self-incompatibility, and the biological mechanisms underlying hybridization. We aimed to characterize pollen tube growth and double fertilization in C. oleifera. The female and male parent cultivars (Huashuo and Xianglin XLC15, respectively) were used for artificial pollination. Growth of the pollen tube in the style, ovary, and ovule from pollination to fertilization and the cytological characteristics of female and male gamete fusion during double fertilization were observed using fluorescence and scanning electron microscopy (SEM). Numerous pollen grains germinated 2 to 4 hours after pollination. The pollen tubes entered the interspaces between the papillar cells, grew along the stylar canal, and aggregated at the one-third site of the style. They grew in the gradually narrowing stylar canal, entering the locule. The tubes turned 90 degrees and entered the embryo sac through the micropyle; subsequently, they entered a degenerated synergid, where the spermatids were released. One sperm nucleus fused with the polar nucleus, forming the primary endosperm nucleus, whereas the other sperm fused with the egg, forming the zygote. The polar nucleus was fertilized earlier than the egg. Double fertilization of C. oleifera is characterized as pre-mitotic gametogony. The current results lay a theoretical foundation for studies concerning the crossbreeding and embryology of C. oleifera and provide fundamental data concerning the reproductive biology of the genus Camellia.