国产日产精品_国产精品毛片_91精品视频在线看_在线播放日韩_欧美电影《轻佻寡妇》

據英國每日郵報報道，日前，最新一項研究表明，甚至在1萬年前的早期人類就掌握了“基因改良”水稻的種植技術。

該研究顯示遠古人類可選擇不同的水稻株，然后將它們的基因混合在一起，形成理想產量的農作物，這將形成較高的產量和易種植性。據悉，這項發現是科學家發現野生水稻基因中含有兩個截然不同的亞屬分支，受變異基因SD1的影響，水稻株的長度被縮短。

日本神戶大學Masanori Yamasaki教授稱，這是近50年里現代水稻培育中最為重要的基因改良，然而我們竟發現1萬年前的早期人類就早已掌握。目前，該項研究報告發表在《美國國家科學院學報》上。

隨著SD1基因的逐步進化改良，水稻將形成更短、更結實的莖干，并生產更多的谷粒。研究人員發現現代培育水稻中混合了一個亞屬分支，這在野生水稻中并不存在。此外，相比之下培育亞屬分支水稻比野生水稻的SD1基因中，前者的遺傳多樣性較低。這表明在早期水稻培育中，SD1基因已經過了人工選擇淘汰。

推薦原文出處：

Proceedings of the National Academy of Sciences    DOI：10.1073/pnas.1019490108

Artificial selection for a green revolution gene during japonica rice domestication

Kenji Asano, Masanori Yamasaki, Shohei Takuno, Kotaro Miura, Satoshi Katagiri, Tomoko Ito, Kazuyuki Doi, Jianzhong Wu, Kaworu Ebana, Takashi Matsumoto, Hideki Innan, Hidemi Kitano, Motoyuki Ashikari, and Makoto Matsuoka

The semidwarf phenotype has been extensively selected during modern crop breeding as an agronomically important trait. Introduction of the semidwarf gene, semi-dwarf1 (sd1), which encodes a gibberellin biosynthesis enzyme, made significant contributions to the “green revolution” in rice (Oryza sativa L.). Here we report that SD1 was involved not only in modern breeding including the green revolution, but also in early steps of rice domestication. We identified two SNPs in O. sativa subspecies (ssp.) japonica SD1 as functional nucleotide polymorphisms (FNPs) responsible for shorter culm length and low gibberellin biosynthetic activity. Genetic diversity analysis among O. sativa ssp. japonica and indica, along with their wild ancestor O. rufipogon Griff, revealed that these FNPs clearly differentiate the japonica landrace and O. rufipogon. We also found a dramatic reduction in nucleotide diversity around SD1 only in the japonica landrace, not in the indica landrace or O. rufipogon. These findings indicate that SD1 has been subjected to artificial selection in rice evolution and that the FNPs participated in japonica domestication, suggesting that ancient humans already used the green revolution gene.

購買進口儀器、試劑和耗材——就在始于2001年的畢特博生物 www.mobfastly.com