柱型苹果生长特性及Co基因定位研究进展

doi:10.3864/j.issn.0578-1752.2017.22.018

摘要/Abstract

摘要： 柱型苹果是一类特殊的矮生类型突变体，其树体矮小、主干粗壮直立、节间短、短枝多，无需修剪、管理方便，是现代苹果产业实现矮化密植栽培获得高产的优良资源。自柱型苹果产生以来，其独特树形的生长特性一直是国内外研究者关注的焦点。当前国内外取得的研究成果主要包括：（1）柱型苹果的生长发育与其内源激素含量密切相关。柱型苹果腋芽中自由态IAA/总IAA的比值明显高于普通型。柱型苹果多发短枝的原因是顶芽和侧芽中玉米素类物质含量较高。柱型苹果树体生长矮小原因可能是赤霉素含量低。（2）苹果的柱形性状是由显性基因Co控制的质量性状，Co位点与枝干、分枝、叶片和果实品质等多种性状连锁成簇。Co精细定位于苹果第10号染色体18.52—19.09 Mb。（3）目前报道的Co有5个候选基因，其中最有希望的候选基因91071转入苹果和烟草中均表现节间变短，但Co是否介入减少侧枝和增加短枝的形成需要进一步验证。由于Co与植物激素代谢和信号传导均密切相关，通过RNAi及转基因等技术验证Co的详细功能，不但可以揭示柱型苹果独特树形生长特性的分子机理，还可以为选育优良品质的柱型苹果提供理论基础。

关键词: 柱型苹果, 生长特性, Co基因定位, 候选基因挖掘

Abstract: Columnar apple is a dwarfed mutant with thick, upright main stems and shortened internodes, and generates short fruit spurs instead of long lateral branches. It is a good resource for high dense planting and high yield production in the modern apple industry. Therefore, to understand its unique growth habit was highly interested for all research groups. The current research achievements are summarized as follows: (1) The growth habits of columnar apple is closely related with its endogenous hormones. The free IAA to total IAA ratio was found higher in the axillary buds of columnar apple trees than in the standard type apple trees. The columnar apple producing high number of spurs is because the higher level of zeatin-like growth substances exists in both apical and lateral shoots. The dwarfed growth phenotype is probably correlated with the lower GA level in the columnar apple trees. (2) The columnar phenotype is controlled by a single dominant allele of the columnar gene, which is clustered with the genes controlling main stem growth, branching habit, leaf feature and fruit quality. The Co gene has been fine-mapped to chromosome 10 within the region of 18.51-19.09 Mb. (3) Five Co candidate genes has been reported till today. As the observation that expression of 91071 in apple and tobacco led to shortened internodes in transgenic plants, 91071 was taken as the most promising Co candidate gene, although more studies are needed to clarify whether the 91071 gene also causes the reduced lateral branches and increased spurs in columnar apple. Since co gene is closed related with both plant hormone metabolism and signal transduction, studies on its biological functions by RNAi and transgenic technologies can not only reveal the molecular mechanism of the unique growth characteristics of columnar apple tree, but also provide the theoretical basis for the molecular breeding of columnar apple with improved quality.

Key words: columnar apple, growth habit, Co gene mapping, mining of candidate genes

梁美霞，乔绪强，郭笑彤，张洪霞. 柱型苹果生长特性及Co基因定位研究进展[J]. 中国农业科学, 2017, 50(22): 4421-4430.

LIANG MeiXia, QIAO XuQiang, GUO XiaoTong, ZHANG HongXia. Research Progresses in mechanisms of Growth Habits and Co Gene Mapping of Columnar Apple (Malus domestica × Borkh.)[J]. Scientia Agricultura Sinica, 2017, 50(22): 4421-4430.

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