草果两型植株的繁育差异研究

草果(Amomum tsaoko)是具有柱头卷曲机制的姜科植物,该研究通过观察和分析传粉者的访花行为、草果的花蜜分泌和最终的结实率,探索其花蜜分泌模式与传粉行为的相互关系,以及对其两型植株繁殖的影响。结果表明:草果两型植株的花蜜分泌在1 d花期的16:40—19:00期间达到高峰;上举型花比下垂型花能够提供更多的花蜜,下垂型花的花蜜分泌受环境温度、光照、湿度的显著影响,其结实率也显著低于上举型花。中华蜜蜂(Apis cerean cerana)是观察点频率最高的有效传粉者,在1 d花期里访花频率呈现双峰模式,访花行为受到温度和湿度的显著影响,78%或18℃较适宜访花。1 d花期中温度、湿度的变化,以及花蜜的动态分泌模式共同促进这一双峰访花模式的形成。草果花蜜分泌模式和双峰访花模式均与草果的柱头卷曲运动匹配,对吸引昆虫精确传粉、维持柱头卷曲机制有重要意义。草果两型植株之间,环境因素对它们花蜜分泌的影响显著不同,导致传粉者不同的访花行为反应和繁殖结果。适当增加居群中上举型植株数量,可能是提高产量的一个有效方法。

Difference of reproduction between the two morphs of Amomum tsaoko(Zingiberaceae)

Observations and analyses were conducted on visitor behavior, nectar production and final percentage of fruit to explore how Amomum tsaoko, a flexistylous ginger, build an insect-plant interrelation to influence on reproduction ofits two morphs. The nectar production of both the morphs reached a peak during 16:40-19:00 in one-day anthesis, al-though the anaflexistylous flowers offered significantly more nectar than the cataflexistylous morph, which was influenced significantly by temperature, light and humidity, and whose fruit-setting rate was significantly lower than the former. The visiting frequency of the effective pollinator ( Apis cerean cerana) was an bimodal visit pattern in one-day anthesis. The bees were significantly affected by both temperature and humidity, 78% or 18℃ was suitable for them to visit. In one-day anthesis, temperature and humidity influence on the bees and the dynamic secretion of nectar of the plant collective-ly promoted the bimodal visit pattern of the bees. Both the rhythms of the nectar secretion of the plant and the bimodal visit pattern of the bees matched with the flexistylous movement of the plant, favoring to the precise pollination and main-taining flexistyly of the plant. Between the two morphs, the influences of the environmental factors on the nectar secretion were significantly different, and had consequently different behavioral responses of the pollinators and the reproductive success. Properly increasing the anaflexistylous morph in a population of the plant would obtain higher prolificacy.