云南地区稻作品种多样性的地理分布格局与不同民族人口分布之间的关系

利用云南地区5285份稻种资源信息和人口普查数据,分析了该地区稻作品种多样性的地理分布格局及其与不同民族人口分布之间的关系。结果表明,云南地区稻作品种的多样性从南到北总体上呈递减趋势;傣族、哈尼族、拉祜族和布朗族人口比重与稻作品种的丰富度密切相关;不同民族文化和稻作文化背景下的人口对传统稻作品种的留存和栽培可能具有不同的影响。

Comparison of Genetic Diversity Between Local Cultivated Aromatic and Non-aromatic Rice in Yunnan Province

[ Objective] The genetic diversity of the local cultivated aromatic rice and non-aromatic rice in Yunnan Province were compared to provide further genetic resources for breeding practice. [Method] Genetic diversity of 10 aromatic rice and 45 non-aromatic rice were analyzed by 64 SSR primers covered on 12 rice chromosomes. [ Result] Per locus 5.44 and 7.98 alleles in average were detected, ranging from 2 to 12 and from 2 to 17 in aromatic and non-aromatic rice, respectively. Average genetic multiplicity index（Hs） was 0.46 and 0.67 respectively. The average polymorphism information content （PIC） was 0.43 and 0.58 in aromatic and non-aromatic rice respectively. [ Conclusion] The results indicated that genetic diversity was higher in non-aromatic rice than in aromatic rice.

Diversity Centers of Rice Cultivar in Yunnan and Their Correlation with Ecological and Cultural Factors

Ecological and cultural factors have strong impacts on the distribution and cultivation of agricultural cultivar., In this paper, the correlation between diversity centers of rice cultivar and ecological, cultural factors was probed, based on datasets of rice cultivar in Yunnan, Southwest China. The results showed that diversity centers of rice cultivar were observed in Southwest Yunnan, South Yunnan and Southeast Yunnan, which may be related to the local culture of rice production and warm, humid climate. For the diversity center in South Yunnan, culture of rice production of Dai and Hani people may play important roles. The diversity center in Southwest Yunnan may relate to the culture of rice production of Dai, Jingpo and Lahu people, and for the diversity center in Southeast Yunnan, Miao, Yao and Zhuang people＇s culture in rice production can not be underestimated. Traditional culture promoted the cultivation of rice cultivars, and high diversity of rice cultivars facilitate the preservation and continuation of the traditional culture as well.

A buried Neolithic paddy soil reveals loss of microbial functional diversity after modern rice cultivation

It has been documented that human activities are causing the rapid loss of taxonomic, phylogenetic, genetic and functional diversity in soils. However, it remains unclear how modern intensive rice cultivation impacts the soil microbiome and its functionality. Here we examined the microbial composition and function differences between a buried Neolithic paddy soil and an adjacent, currently-cultivated paddy soil using high throughput metagenomics technologies. Our results showed that the currently cultivated soil contained about 10-fold more microbial biomass than the buried one. Analyses based on both 16S rRNA genes and functional gene array showed that the currently cultivated soil had significantly higher phylogenetic diversity, but less functional diversity than the buried Neolithic one. The community structures were significantly different between modern and ancient soils, with functional structure shifting towards accelerated organic carbon （C） degradation and nitrogen （N） transfor- mation in the modem soils. This study implies that, modern intensive rice cultivation has substantially altered soil microbial functional structure, leading to functional homogenization and the promotion of soil ecological functions related to the acceleration of nutrient cycling which is necessary for high crop yields.

DNA methylation polymorphism and stability in Chinese indica hybrid rice

Conventional rice breeding has long focused on exploiting the DNA sequence diversity.However,epigenetic diversity,reflected particularly in DNA methylation,can also contribute to phenotypic variation and should not be overlooked in rice breeding.In this study,20 parental lines of indica rice,which are widely used in hybrid rice breeding in China,were analyzed to investigate variations of DNA methylation and its inheritance.The results revealed a wide diversity in DNA methylation among these breeding lines.A positive correlation was seen between DNA methylation and genetic diversity.Furthermore,some of the methylated DNA was inherited in the subsequent generation,regardless of whether they were produced by selfing or hybrid-crossing.This study provides insight into the methylation patterns in rice,and suggests the importance of epigenetic diversity in rice breeding.