爱玉子与其传粉小蜂共生体系的生态修复

Ficus awkeotsang Makino is a special fruit tree introduced from Taiwan. This fig tree has a mutualistic symbiosis with its pollinator, Wiebesia pumilae (Hill) Wieb. The female flowers can only be pollinated by the fig wasps for initiating fruits, and the fig wasps can only oviposit in the gall ovaries within the male syconia for the production of their offspring. Lacking of pollinating wasps would definitely break down the pollination chain, leading to damage the mutualistic system. A low overlap between the short/concentrated period of wasps’ flying off and the long/scattered female phase of both the female and male trees is a main cause for the shortage of the symbiotic wasps. Our attempts will be made: 1) to improve our understanding on correlation and synchronism of structure, morphology, physiology and ecology between the fig inflorescence and wasps developments, to difinate environmental factors affecting their coordinated development through a phenology investigation of reproduction. 2) to fulfil the wasps’ flying off timely and quantitatively from April to December through creating a semi-artificial incubation (SAI) model by which the isolated inflorescence fruits are incubated in climate room as the wasps developing into pupal stage, and the developmental duration (extending or shortening) of wasps could be controled via adjusting environmental factors affecting their developments. 3) to explore the possibility of an alternative wasps’s pollinating or laying eggs inside the female/male syconia by introducing Wiebesia spp.3 (a cryptic species of wasps in symbiosis with Ficus pumila L.) into the syconia in order to widen the source of the wasps in the season when the pollinating wasps appear to be shortage. 4) to monitor and verify the viability, sex rate and fertility of the semi-artificial incubated (SAI) wasps and their offspring (F1, F2) in field trial as well as the effect of the F2 on fruiting rate and quality by bagging the flying SAI wasps and then introducing them into the male syconia in the female phase for laying eggs. It is expected to prolong the period of the wasps flying out from the male syconia, to satisfy a high overlap between D phase of the male syconia and B phase of female/male syconia, so as to restore and improve the fig-wasps symbiosis, lower the fig fruit-falling rate, achieve high yield cultivation, as well as to decrease the number of cultivated male trees and increase the economic benefit of the arable land.

爱玉子为特种果树，与其传粉小蜂为共生关系。爱玉子传粉蜂出飞期短而集中，与其雌、雄株长而分散的雌花期重叠度低，是造成共生体系小蜂缺失，进而榕-蜂共生体系损毁的主要原因。本项目 ①开展繁殖物候研究，了解花序发育与小蜂发育在结构、形态、生理、生态等方面的相关性与同步性，明确影响两者协同发育的环境因子； ②建立榕小蜂半人工培养模式，通过调节影响小蜂发育的环境因子，实现对小蜂发育时长的双向（延长/缩短）调控； ③在缺乏爱玉子传粉蜂季节，引入薜荔传粉蜂（W. spp3种群），探讨薜荔传粉蜂在爱玉子共生体系中生存与繁衍的可能性，以拓宽蜂源； ④开展田间实验，观测半人工培养小蜂的活力，探究子代（F1，F2）小蜂的性比、繁殖力与传粉力，以及F2代蜂对雌株结实率和品质的影响，以期延长雄株的小蜂出飞期，实现雄株D期与雌/雄株B期的高度重叠，从而修复共生体系，实现高产栽培；减少雄株栽培数量，提高土地效益。

爱玉子为引种自台湾的特种果树，爱玉子与其传粉小蜂为共生关系，只有经小蜂传粉的爱玉子雌花序方可结实，而小蜂也必须产卵于爱玉子雄花序的瘿花子房内才能繁衍后代，小蜂的缺失必定造成共生关系的损毁。爱玉子传粉小蜂出飞期短而集中，与爱玉子雌、雄株长而分散的雌花期重叠度低，是造成共生体系小蜂缺失的主要原因。本项目将①通过开展繁殖物候研究，了解爱玉子花序发育与其传粉小蜂发育在结构、形态、生理、生态等方面的相关性与同步性，明确影响两者协同发育的环境因子；②建立榕小蜂半人工培养模式，将小蜂发育进入蛹期的雄果离体移入室内培养，通过调节影响小蜂发育的理化因子，实现对小蜂发育时长的双向(延长/缩短 )调控，以期在4月至12月间定时定量调控小蜂出飞；③探讨薜荔传粉小蜂在爱玉子雌花期雌/雄果内传粉/产卵的可能性，以拓宽蜂源；④开展田间实验，将调控出飞的小蜂套袋引入雌花期雄花序内产卵，观测半人工培养的小蜂的活力，探究其子代（F1，F2）小蜂的性比和繁殖力，以及F2小蜂对雌株结实率和品质的影响，以期延长雄株的小蜂出飞期，实现雄株D期与雌/雄株B期的高度重叠，从而修复与维系爱玉子-传粉小蜂共生体系，降低爱玉子的落果率，实现高产栽培；同时减少单位面积雄株的栽培数量，提高土地效益。