普通野生稻在中國的分布跨越了較大的地理范圍,，表現(xiàn)出明顯的生態(tài)群變異,，從而為研究普通野生稻沿地理分布格局及其適應(yīng)機(jī)制，驗(yàn)證環(huán)境因子,、生理因子和遺傳因子對(duì)物種分布格局的影響提供了合適的材料,。
中科院武漢植物園濕地生態(tài)學(xué)科組博士研究生周雯在劉貴華研究員的指導(dǎo)下,，對(duì)中國6個(gè)省份34個(gè)普通野生稻自然種群的形態(tài)性狀進(jìn)行了考察，并于普通野生稻中國分布區(qū)的最南部（海南陵水）和北緣以外（湖北武漢）分別進(jìn)行了同質(zhì)種植園的移栽試驗(yàn),，以考查不同地理種群個(gè)體移栽后的響應(yīng)情況,。結(jié)果表明，表征普通野生稻生殖特征的種子大小與緯度和經(jīng)度正相關(guān),，表征光合特征的劍葉面積與緯度負(fù)相關(guān),，這兩個(gè)性狀的地理格局主要與溫度的地理變化關(guān)聯(lián)。移栽試驗(yàn)結(jié)果顯示,，種子大小,、劍葉面積、劍葉形態(tài)以及每穗穎果數(shù)的地理變異是由遺傳分化和表型可塑性共同作用的結(jié)果,。在南部的陵水同質(zhì)園中,，所有移栽種群個(gè)體均能成活并完成有性繁殖過程，而在北部的武漢同質(zhì)園中只有65%的種群繁殖成功,，58%的種群成功越冬,，不成功的種群主要是南部種群。綜合以上結(jié)果,，研究人員認(rèn)為,，對(duì)極端低溫的耐受性和生殖與生長之間不對(duì)稱的變化是限制普通野生稻向北擴(kuò)張的主要因素。本研究結(jié)果對(duì)于理解普通野生稻地理分布限制的形成機(jī)制及其對(duì)全球變化的響應(yīng)趨勢(shì)具有重要意義,。研究結(jié)果在Journal of Ecology上在線發(fā)表,。
本項(xiàng)研究獲得中科院戰(zhàn)略性科技先導(dǎo)專項(xiàng)（XDA05130403）、財(cái)政部戰(zhàn)略資源科技支撐運(yùn)行專項(xiàng)（KSCX2-YW-Z-1005）及國家自然科學(xué)基金（NSFC30970469）的支持,。
普通野生稻北部同質(zhì)園移栽種群的（a）越冬存活率和（b）有性繁殖成功率與其來源緯度之間的關(guān)系,。虛線表示各位點(diǎn)自然種群的歷史冬季最低溫。在第二個(gè)生長季初始時(shí)出現(xiàn)一片或多片綠葉就認(rèn)定該植株成功越冬,。每個(gè)種群出現(xiàn)一個(gè)或多個(gè)植株抽穗的情況就認(rèn)定為有性繁殖成功,。（生物谷 Bioon.com）
生物谷推薦的相關(guān)摘要
Journal of Ecology DOI: 10.1111/1365-2745.12143
Geographic variation and local adaptation in Oryza rufipogon across its climatic range in China
Wen Zhou, Zhixiu Wang, Anthony J. Davy, Guihua Liu
1. Variation in plant functional traits and demographic behaviour in populations of widely distributed species on geographic gradients may be key to understanding their geographic range limits. Oryza rufipogon, a wild progenitor of rice, occurs in discrete wetland populations over a wide latitudinal range in China.
2. We examined correlations between plant functional traits, latitude, longitude and climatic variables in 34 populations of O. rufipogon across its northern range limit. We also investigated the responses of individuals from all populations after transplantation to two experimental gardens: one north of its range and the other in the extreme south.
3. Seed mass in the field was positively correlated with latitude and longitude, whereas flag-leaf area was negatively correlated with latitude; both effects could be explained largely as a response to temperature. Transplantation revealed that both plasticity and population differentiation contributed to geographical variation. All populations reproduced and overwintered in the southern garden but, in the northern garden, only populations from the northern range were able to reproduce (65%) and survive the winter (58%).
4. Synthesis. Environmentally-determined variation in plant functional traits is complex, with both plastic trade-offs between traits and genetic differentiation between populations contributing to the location of the northern limit of Oryza rufipogon.
