導(dǎo)讀：8月29日,，一國(guó)際科研小組報(bào)道稱他們繪出了廣受人們喜愛(ài)的“金冠蘋果”的基因組草圖。這將有助于從基因水平上分析蘋果性狀,，培育更多蘋果新品種,。
生物谷推薦原文索引<<<
Nature Genetics doi:10.1038/ng.654
The genome of the domesticated apple (Malus × domestica Borkh.)
Riccardo Velasco etc.
據(jù)新華社報(bào)道稱，蘋果基因組中含有7億多個(gè)堿基對(duì),，其中有大段重復(fù)的基因,。研究人員說(shuō)，也許是大量的重復(fù)基因使蘋果具有較多的染色體數(shù)目,。與蘋果同屬薔薇科的桃和草莓等水果的染色體數(shù)在7到9之間,，而蘋果的染色體數(shù)為17。
通過(guò)基因分析,，研究人員還查明了蘋果的“身世”,。蘋果與其他水果“親戚”之間的進(jìn)化分叉可能發(fā)生在五六千萬(wàn)年前，而這正是地球上發(fā)生大災(zāi)難的時(shí)候,。這場(chǎng)大災(zāi)難導(dǎo)致恐龍滅絕,。蘋果的“祖先”植物可能是為了適應(yīng)大災(zāi)難后的環(huán)境,，逐步發(fā)生基因變化，最終進(jìn)化成了今天的蘋果樹,。
正是這些與其他水果不同的基因決定了蘋果獨(dú)特的風(fēng)味和口感,。此次繪出的蘋果基因組草圖，將有助于今后采用基因手段改良蘋果,，比如培育更脆,、更多汁的蘋果品種。
蘋果是世界上最重要的水果之一,。據(jù)介紹,，現(xiàn)在全球每年蘋果產(chǎn)量超過(guò)6000萬(wàn)噸。（生物谷Bioon.com）
英文摘要
We report a high-quality draft genome sequence of the domesticated apple (Malus × domestica). We show that a relatively recent (>50 million years ago) genome-wide duplication (GWD) has resulted in the transition from nine ancestral chromosomes to 17 chromosomes in the Pyreae. Traces of older GWDs partly support the monophyly of the ancestral paleohexaploidy of eudicots. Phylogenetic reconstruction of Pyreae and the genus Malus, relative to major Rosaceae taxa, identified the progenitor of the cultivated apple as M. sieversii. Expansion of gene families reported to be involved in fruit development may explain formation of the pome, a Pyreae-specific false fruit that develops by proliferation of the basal part of the sepals, the receptacle. In apple, a subclade of MADS-box genes, normally involved in flower and fruit development, is expanded to include 15 members, as are other gene families involved in Rosaceae-specific metabolism, such as transport and assimilation of sorbitol.
