摘要
【目的】通过比较不同西番莲品种(系)自交和异交授粉后花粉萌发及花粉管生长差异和授粉亲和性的强弱,阐明不同亲和性类型的花粉管生长行为,为西番莲授粉及杂交育种提供参考。【方法】以主栽品种台农1号(TN)和编号为H2、MB、H6、ZS的西番莲品系为试验材料,试验共设置4个自交授粉组合,分别为TN、H2、MB、H6自交,以及6个异交授粉组合,分别为H6×MB、H6×TN、MB×H6、MB×TN、ZS×MB、ZS×H6,分别对授粉后0.5~24 h的花粉管进行荧光显微观察并计算授粉亲和性指数,同时对雌蕊进行解剖观察,并统计H6×MB等4个组合的坐果率。【结果】(1)西番莲雌蕊柱头上密布乳突,花粉管穿过柱头乳突细胞间隙进入柱头引导组织,引导组织呈漏斗形,从柱头延伸至花柱基部。(2)具有亲和性的西番莲自交和异交组合的花粉粒附着在柱头后,萌发出花粉管进入柱头乳突,之后经过柱头和花柱引导组织,于授粉后18~24 h进入胚珠;而具有不亲和性的西番莲自交和异交组合的花粉粒可以附着在柱头上并萌发出花粉管,但花粉管出现末端膨大变粗的畸形形态,不能正常伸长,最终只能停留在柱头乳突中,表现出孢子体不亲和类型的特征。(3)4个自交授粉组合的授粉亲和性为TN>H2>MB>H6,其中H6为自交不亲和类型;6个异交授粉组合的授粉亲和性为H6×MB>H6×TN、MB×H6>MB×TN、ZS×MB>ZS×H6,其中H6×TN为异交不亲和类型;除MB×TN外,H6×MB、H6×TN、MB×H6的坐果率与花粉管观察结果一致。(4)亲和性组合的花粉管生长会伴随规则的胼胝质塞;柱头乳突的胼胝质堆积与授粉亲和性存在关联,表现出乳突细胞胼胝质堆积量随着亲和性的减弱而增加。【结论】具亲和性的西番莲自交和异交组合于授粉后18~24 h花粉管进入胚珠,而不亲和组合的花粉管畸形无法穿过柱头乳突;柱头乳突细胞胼胝质堆积增多则亲和性降低。
【Objective】This study summarized the pollen tube growth behavior of different compatibility types by comparing the differences in pollen germination,pollen tube growth and the strength of pollination compatibility after self and cross-pollination among different passion fruit varieties(lines),so as to provide reference for passion fruit pollination and cross breeding.【Methods】In this experiment,the main cultivar of China,Tainong 1(TN)and passion fruit lines numbered as H2,MB,H6 and ZS were used as test materials.Four self-pollination combinations were set up,namely TN,H2,MB and H6 self-pollination,and six cross-pollination combinations(female parent×male parent):H6×MB,H6×TN,MB×H6,MB×TN,ZS×MB and ZS×H6,respectively.Pollen behaviors 0.5-24 hours after pollination were observed and photographed under a fluorescence microscope.We counted the number of pollen tubes germinating on the stigma surface,entering into the stigma transmitting tissue,reaching the middle of the style and entering the ovary,and calculated the pollination compatibility index.At the same time,the pistil was dissected and observed,and the fruit setting rate of four combinations including H6×MB,H6×TN,MB×H6 and MB×TN was calculated.【Results】(1)The pistil of passion fruit consisted of stigma,style and ovary.The stigma was densely covered with papillae.The pollen tube passed through the gap between the stigma papilla cells and entered the stigma transmitting tissue.The transmitting tissue was funnel-shaped,extending from the stigma to the base of the style.The style had three branches,connecting to the ovary.The ovule in the ovary was pear-shaped,the micropyle was at the base of the funicle,the embryo sac was long oval,and the embryo sac was covered with the integument.(2)We found that in the self and cross-pollination combinations of passion fruit with affinity,the pollen grains attached to the stigma,sprouted pollen tubes into the stigma papilla,then passed through the stigma and style transmitting tissue,and entered the ovule 18-24 hours after pollination.The pollen germination rate and pollen tube growth rate of different combinations were different.The“fast”pollen grains germinated 0.5 hour after pollination and reached ovary 8 hours after pollination,while the“slow”pollen grains germinated 6 hours after pollination and the pollen tube did not reach the ovary 24hours after pollination.However,in case of incompatible passion fruit,either self or cross-pollination combinations,pollen grains could attach to the stigma,sprout and sent forth pollen tubes,but the bottom of the pollen tube expanded,could not elongate normally,and finally could only stay in the stigma papilla,which showed the characteristics of sporophyte incompatibility type.(3)The average pollination compatibility index of 8 to 24 hours after self-pollination of TN was the highest(1.25),and that of H6×TN was the lowest(0.01).The pollination compatibility trend of the four self-pollination combinations was TN>H2>MB>H6,and H6 was self-incompatibility type.The pollination compatibility trend of the six cross-pollination combinations was H6×MB>H6×TN,MB×H6>MB×TN,ZS×MB>ZS×H6,and H6×TN was the cross-incompatibility type.Except MB×TN,the fruit setting trend of H6×MB,H6×TN and MB×H6 was consistent with pollen tube observation.In addition,we found that there were differences in compatibility and fruit drop rates of reciprocal crosses combinations.For example,H6 as the female parent and MB as the male parent had higher compatibility and lower fruit drop rate,compared with H6 as the male parent and MB as the female parent.So the selection of parents was related to pollination compatibility and fruit setting of cross-pollination combinations.(4)Pollen tube elongation was accompanied by callose accumulation.Pollen tube growth of compatible combinations was accompanied by regular callose plugs.Callose accumulation in stigma papilla was correlated with pollination compatibility,indicating that callose accumulation in papilla cells increased with a decreasing compatibility.For example,a large amount of callose accumulation was observed in the stigma papilla24 hours after pollination in H6 self-pollination and H6×TN incompatibility combinations,while no obvious callose accumulation was observed in the stigma papilla in TN self-crossing and H2 self-pollination combinations with the highest self-pollination compatibility.【Conclusion】The pollen tubes of the self and cross-pollination combinations entered the ovules 18-24 hours after pollination,while the pollen tubes of the incompatible combinations could not pass through the stigma papilla,so it belonged to sporophyte incompatibility type.The affinity decreased with the increase of callose accumulation of stigma papilla cells.The affinity can be identified by the number of germinating pollen grains,initiation time,pollen tube growth rate and callose accumulation in stigma papilla.
作者
田青兰
吴艳艳
张英俊
刘洁云
黄伟华
温放
韦毅刚
牟海飞
TIAN Qinglan;WU Yanyan;ZHANG Yingjun;LIU Jieyun;HUANG Weihua;WEN Fang;WEI Yigang;MOU Haifei(Biotechnology Research Institute,Guangxi Academy of Agricultural Sciences,Nanning 530007,Guangxi,China;Guangxi Institute of Botany,Guangxi Zhuang Autonomous Region&Chinese Academy of Sciences,Guilin 541006,Guangxi,China)
出处
《果树学报》
CAS
CSCD
北大核心
2023年第1期98-110,共13页
Journal of Fruit Science
基金
广西科技重大专项(桂科AA22068091、桂科AA22068091-1)
广西自然科学基金(2021GXNSFBA075044)
广西农业科学院科技发展基金(桂农科2021JM80)
广西农业科学院基本科研业务专项(桂农科2021YT089)。
关键词
西番莲
自交
异交
授粉亲和性
花粉管
Passion fruit
Self-pollination
Cross-pollination
Pollination compatibility
Pollen tube
