中国云南元阳哈尼梯田种植的稻作品种多样性

Diversity of paddy rice varieties from Yuanyang Hani's terraced fields in Yunnan,China

稻作是我国第一大粮食作物,近年来,选育品种的大面积单一化种植,导致种植的稻作品种遗传基础狭窄,多样性下降,已经受到关注。然而在一些少数民族地区,如元阳哈尼梯田,当地民族的传统文化习俗已经保护了当地的水稻资源,高度的多样性依然存在。采用半问卷式和农村参与式评价方法(PRA),在村寨和农户两个水平,调查分析中国云南省元阳哈尼梯田种植的稻作品种多样性,尤其是当前仍在种植的传统品种的多样性,为稻作传统品种多样性农家就地保护提供典型范例。结果表明,在调查的30个村寨750户中,共种植135个具不同名称的水稻品种(组合),包括100个传统品种,12个杂交稻组合和23个现代育成品种;种植传统品种的面积占总稻作面积的56.2%;平均每个村寨种植9.7个品种,最多的达19个,最少仅4个;每个村寨至少种植2个传统品种和1个现代品种;种植最多的是传统品种"老粳糯",有12个不同村寨种植;大多数传统品种仅有12个不同村寨种植。有11个村寨(占的30个村寨36.7%)的所有农户均种植传统品种。在农户级水平上,有611户(占81.5%)种植传统品种;有391户(占52.1%)同时种植传统品种和现代品种,其种植传统品种与现代品种的面积比例平均为1/2;仅种植传统品种的有220户(占29.3%)。平均每户种植2.2个品种(组合),最多的农户种植5个品种,包括3个传统品种,1个现代常规品种,1个杂交稻组合。传统品种的丰富度,村寨平均为5.9,最高达12,而农户平均为1.541;传统品种的均匀度,村寨平均为0.670,农户平均为0.192;不同村寨种植传统品种的差异度平均值为0.702。其中太阳老寨、新寨村、欧乐、多沙和上马点等5个村寨传统品种的丰富度与均匀度均较高,在稻作传统品种农家保护中扮演着重要角色。在村寨和农户水平,传统品种丰富度与均匀度的相关性均呈极显著正相关(r=0.627,0.925);村寨传统品种丰富度与农户数呈极显著正相关(r=0.473);村寨农户年人均纯收入分别与村寨传统品种丰富度和农户数呈极显著和显著负相关(r=-0.570,-0.370*)。在如此小的耕地面积(142.29hm2)上,当前生产上仍种植着如此丰富的稻作传统品种,实属少见。高度异质的生态环境和民族文化习俗是哈尼梯田传统稻作品种多样性种植的重要因素,建议将元阳哈尼梯田作为稻作传统品种多样性农家就地保护区。

Rice is the largest staple food crop in China.In recent years,the adoption of improved varieties on a large-scale led to a narrowing of the rice genetic base and a decreased diversity of traditional rice varieties growing in farmers＇ fields,such change has been widely paid on.Some areas of high rice diversity due continue to exist,in particular in areas of minority ethnic groups where cultural tourism has protected these remaining rice resources.Yuanyang Hani＇s terraced fields is one such area where traditional rice varieties continue to be managed by the local population.In the present study,the diversity of paddy rice varieties,in particular traditional varieties,grown in Yuanyang Hani＇s terraced fields at both the household and village levels was investigated through participatory rural appraisal（PRA）,questionnaires and semistructured interview for data collection in order to illustrate an example for the diversity of rice landrace of in-situ conservation.A total of 135 rice varieties with different names including 12 hybrid crosses,23 modern bred varieties and 100 landraces were found to be cultivated by the representative 750 households distributed over 30 villages in Yuanyang.The proportion of area grown to landraces（traditional varieties） was up to 56.2% of the total area of rice cultivation for these households.The average number of varieties per village was 9.7,ranging from 4 to 19 varieties per village.Each village grew at least two traditional varieties and one modern bred variety.The most frequent growing landrace was ＂Lao Jing nuo＂,cultivated by 12 different villages.For the other landraces,a landrace was often grown by only one or two different villages.In 11 villages of the total 30 villages surveyed（36.7%）,all households planted at least one traditional variety.At the household level,611 of the 750 households investigated（81.5%） grew traditional varieties.391 households grew both landraces and modern bred varieties accounted for 52.1% of total 750 households,the proportion of the area grown to landrace versus modern bred varieties was occupying 1 /2 for only the households that grew both landraces and modern varieties,while only 220 households growing traditional varieties accounted for 29.3%.The average number of varieties grown per household was 2.2 with a maximum 5 varieties,including one hybrid,one improved inbred variety and three landraces.The richness and evenness of landrace were 5.9 and 0.670,respectively at village level,Richness and evenness at the household level was 1.541 and 0.192,respectively.The average divergence of landrace was 0.702 at village level.The richness and evenness of landrace were highest in five villages：Taiyanglaozhai,Xinzhaicun,Oule,Duosha and Shangmadian.This indicates that the five villages have played greater roles in on-farm conservation of rice traditional varieties.Significantly positive correlation between richness and evenness of landraces were showed,with r = 0.627 at village level and r = 0.925 at household level.There was also significantly positive correlation r = 0.473 between richness of landraces at village level and number of households.However,at the village level,there were significant negative correlations with r =-0.570 and r =-0.370＊ between either landrace richness at village level or the number of households,and annual net income per person,respectively.Yuanyang is a rare area in China where so many landraces are still under cultivation within such a small area of 142.29 hm2.High heterogeneity of ecological environments and diversity of local traditional customs might be key factors that have affected the diversity of traditional rice varieties grown in Yuanyang Hani＇ s terraced fields.It is suggested that Yuanyang Hani＇ s terraced fields should be protected,and serve as a basis of on-farm conservation region for diversity of traditional rice varieties.