关于香蕉正濒临灭绝境地的报道很有可能被严重夸大了。至少这是一个科学家小组所希望的。这个小组的科学家终于完成了香蕉基因组的测序,并指望借此来获得新的抗性基因,以使香蕉免遭它的两个真菌“敌人”——黄叶病和黑斑病的侵袭。
世界上超过一半的香蕉和几乎所有出口到美国和欧洲的香蕉,都属于一种名为“卡文迪许”的香蕉。
“卡文迪许”香蕉没有种子,不能进行有性繁殖。这意味着所有香蕉的基因都是相同的,而且都同样容易受到真菌的威胁。
同时,“卡文迪许”香蕉拥有三条染色体,这使得它的基因组测序非常困难。
因此,在一项于7月12日在线发表在《自然》(Nature)志上的最新研究中,研究人员对另一个被称为DH Pahang的香蕉品种的基因组进行了测序。
DH Pahang香蕉是形成“卡文迪许”品种的三种香蕉之一,而且它对威胁“卡文迪许”香蕉的黄叶病具有很强的抵抗力。
更重要的是,正如右图中DH Pahang香蕉的种子所示,它有着完整的“性生活”。这意味着,DH Pahang香蕉可以被用来培育新的品种,或许其生命力要比今天的香蕉更为顽强。(生物谷Bioon.com)
doi:10.1038/nature11241
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The banana (Musa acuminata) genome and the evolution of monocotyledonous plants
Angélique D’Hont; France Denoeud; Jean-Marc Aury; Franc-Christophe Baurens; Fran?oise Carreel; Olivier Garsmeur; Benjamin Noel; Stéphanie Bocs; Ga?tan Droc; Mathieu Rouard; Corinne Da Silva; Kamel Jabbari; Céline Cardi; Julie Poulain; Marlène Souquet; Karine Labadie; Cyril Jourda; Juliette Lengellé; Marguerite Rodier-Goud; Adriana Alberti; Maria Bernard; Margot Correa; Saravanaraj Ayyampalayam; Michael R. Mckain; Jim Leebens-Mack; D
Bananas (Musa spp.), including dessert and cooking types, are giant perennial monocotyledonous herbs of the order Zingiberales, a sister group to the well-studied Poales, which include cereals. Bananas are vital for food security in many tropical and subtropical countries and the most popular fruit in industrialized countries1. The Musa domestication process started some 7,000 years ago in Southeast Asia. It involved hybridizations between diverse species and subspecies, fostered by human migrations2, and selection of diploid and triploid seedless, parthenocarpic hybrids thereafter widely dispersed by vegetative propagation. Half of the current production relies on somaclones derived from a single triploid genotype (Cavendish)1. Pests and diseases have gradually become adapted, representing an imminent danger for global banana production3, 4. Here we describe the draft sequence of the 523-megabase genome of a Musa acuminata doubled-haploid genotype, providing a crucial stepping-stone for genetic improvement of banana. We detected three rounds of whole-genome duplications in the Musa lineage, independently of those previously described in the Poales lineage and the one we detected in the Arecales lineage. This first monocotyledon high-continuity whole-genome sequence reported outside Poales represents an essential bridge for comparative genome analysis in plants. As such, it clarifies commelinid-monocotyledon phylogenetic relationships, reveals Poaceae-specific features and has led to the discovery of conserved non-coding sequences predating monocotyledon–eudicotyledon divergence.