濒危植物金花猕猴桃繁殖生物学初步研究

Reproductive biology of endangered plant Actinidia chrysantha

关键词:  金花猕猴桃, 繁殖生物学, 物候, 开花结果习性, 传粉

Key words:  Actinidia chrysantha, reproductive biology, phenological, blossom and fruiting habit, pollination

摘要:

繁殖生物学是目前濒危植物保护生物学研究的重点领域之一,金花猕猴桃(Actinidia chrysantha)是猕猴桃属濒危物种之一,目前未见其繁殖生物学相关报道。因此,该文以分布于花坪国家级自然保护区的野生金花猕猴桃为研究对象,用游标卡尺测量了花器官及果实形态,通过野外观察记录了其物候、访花昆虫及开花结果习性,用人工授粉和套袋法确定其传粉媒介,开展田间播种试验确定种子繁殖力,对其繁殖生物学开展了较为系统的研究。结果表明:金花猕猴桃物候因海拔高度不同而不同,较低海拔地区5月中下旬开花,高海拔地区5月下旬至6月上旬开花,花期持续7～10 d,果实每年9月下旬至10月上旬成熟; 雄株花枝率76.5%,雌株果枝率61.9%,果实长圆柱形、短圆柱形或椭圆形,平均单果重7.34～27.53 g,最大果重35.0 g; 金花猕猴桃为虫媒和风媒共同授粉,主要访花昆虫有蜜蜂科、细蜂科、鼻蝇亚科、食蚜蝇科、蜡蝉科、大蚊科长脚蚊属昆虫等; 金花猕猴桃种子发芽率低,参试的3个居群的种子发芽率存在差异,分别为花坪17.5%,资源车田15.36%,贺州姑婆山0; 4种不同种子处理方式中,低温+GA₃处理的种子发芽率(22.67%)最高。综上所述,金花猕猴桃不存在传粉障碍,种子萌发率低可能是致其濒危的重要原因。该研究结果为保护金花猕猴桃种质资源提供了科学依据。

Abstract:

At present,reproductive biology has become one of the important research field of conservation biology of endangered plant, Actinidia chrysantha was one of endangered species in Actinidia genus, but there was no reproductive biology related reports about it till now. In this study, took wild A. chrysantha plants which distributed in Hua-ping National Nature Reserve as test material, its floral organ and fruit shape were measured with a vernier caliper; based on field observations recorded its phonological period, flower visiting insect, blossom and fruiting habit; determine its pollinators by artificial pollination and bagging experiments; through field sowing test, determine the seed reproductive capacity. The results showed that phenological characters of A. chrysantha were different with the altitude varying. At lower altitude area its flowering in the middle or late May, while at the higher altitude area its flowering in the late May to early June, flower season lasted for 7-10 d; fruit ripening in late September to early October of every year; spray rate of the male plants was 76.5%, fruit branch rate of female plants was 61.9%, the fruit shape was long column, short column or oval, the average weight of single fruit was 7.34-27.53 g, the maximum fruit weight was 35.0 g; its pollinated by insects and wind in common, the main pollinators including Apidae, Prpductotrupidae, Rhiniinae, Syrphidae, Fulgoridae, Ctenacroscelis of Tipulidae insects etc.; its germination rate of seeds was low, germination rate of three tested populations Huaping, Chetian of Ziyuan County and Gupo Mountain of Hezhou were 17.5%, 15.36% and 0, respectively. In the 4 kinds of seed processing method, the treatment that the seeds was stored at 0-5 ℃ in the refrigerator and before sowing with 1 500 mg·L^-1 gibberellin(GA₃)soaked for 2 h, had the highest germination rate(22.67%). In summary, there was no pollination barrier in the reproductive process of Actinidia chrysantha, low germination rate may be an important cause of A. chrysantha endangered. Therefore, this study provides scientific basis for the protection of A. chrysantha germplasm resources. At present,reproductive biology has become one of the important research field of conservation biology of endangered plant, Actinidia chrysantha was one of endangered species in Actinidia genus, but there was no reproductive biology related reports about it till now. In this study, took wild A. chrysantha plants which distributed in Hua-ping National Nature Reserve as test material, its floral organ and fruit shape were measured with a vernier caliper; based on field observations recorded its phonological period, flower visiting insect, blossom and fruiting habit; determine its pollinators by artificial pollination and bagging experiments; through field sowing test, determine the seed reproductive capacity. The results showed that phenological characters of A. chrysantha were different with the altitude varying. At lower altitude area its flowering in the middle or late May, while at the higher altitude area its flowering in the late May to early June, flower season lasted for 7-10 d; fruit ripening in late September to early October of every year; spray rate of the male plants was 76.5%, fruit branch rate of female plants was 61.9%, the fruit shape was long column, short column or oval, the average weight of single fruit was 7.34-27.53 g, the maximum fruit weight was 35.0 g; its pollinated by insects and wind in common, the main pollinators including Apidae, Prpductotrupidae, Rhiniinae, Syrphidae, Fulgoridae, Ctenacroscelis of Tipulidae insects etc.; its germination rate of seeds was low, germination rate of three tested populations Huaping, Chetian of Ziyuan County and Gupo Mountain of Hezhou were 17.5%, 15.36% and 0, respectively. In the 4 kinds of seed processing method, the treatment that the seeds was stored at 0-5 ℃ in the refrigerator and before sowing with 1 500 mg·L^-1 gibberellin(GA₃)soaked for 2 h, had the highest germination rate(22.67%). In summary, there was no pollination barrier in the reproductive process of Actinidia chrysantha, low germination rate may be an important cause of A. chrysantha endangered. Therefore, this study provides scientific basis for the protection of A. chrysantha germplasm resources.