莲藕多分枝形成机理及功能基因发掘

Sacred lotus (Nelumbo nucifera Gaertn.) is a kind of special vegetable in China, and increased yield is an important goal of sacred lotus breeding. Flower lotus ‘20140424’ has one more lateral branch (the second lateral branch) located in the boundary zone that separates the main branch from another lateral branch (the first lateral branch), this phenotype is quite different from that of the normal sacred lotus resources. Multiple shoot branches have the potential to improve all the yields of rhizome lotus, seed lotus and flower lotus. ‘20140424’ has been separately crossed with four normal sacred lotus as male parent and F1 seeds have been obtained. In the present study, a segregating population (F1 or F2) needs to be developed and on the basis of the whole genome sequences, the following studies will be carried out: whole genome resequencing of DNA from two bulked populations will be used to rapidly map the loci and candidate genes in control of the second lateral branch; the characteristic of the second lateral branch in different development period will be analyzed by paraffin sections in order to determine the cytological basis and critical period of the genesis of the second lateral branch, furthermore, candidate genes should be validated in the critical period by qRT-PCR. These findings obtained above will be important for a better understanding of the molecular mechanisms underlying the second lateral branch and provide theoretical basis for genetic improvement of sacred lotus resources. ‘20140424’ can be used as a high yield material for sacred lotus breeding.

莲藕（Nelumbo nucifera Gaertn.）是我国特色蔬菜，增产是莲藕育种的一项重要目标。本团队前期发现花莲‘20140424’具有多分枝现象，在主枝和侧枝之间长出第三枝，与正常莲藕资源（只具有主枝和侧枝）明显不同。增加分枝数对藕莲、花莲及子莲均有重要作用，有望增加其产量。本项目前期已利用多分枝‘20140424’为父本，与4个正常分枝莲藕品种杂交，获得了F1代种子。本项目拟获得性状分离的F1或F2代，并以其为材料，在具有莲藕基因组草图的基础上开展以下研究：利用重测序BSA技术对控制莲藕多分枝的基因进行初步定位和分析；基于石蜡切片分析多分枝腋芽发育各时期特征和动态过程，确定多分枝发生的细胞学基础和关键时期，并在该时期对候选基因进行qRT-PCR验证。通过以上研究不仅丰富和加深了对莲藕多分枝形成机制的理解，还为莲藕高产种质的遗传改良提供理论基础和优良的基因资源，具有实际应用价值。