Effects of Alternative Partial Root-zone Irrigation and Nitrogen Fertilizer on Plukenetia volubilis Seedlings

This study was aimed to investigate the effects of alternative partial rootzone irrigation and nitrogen fertilizer on the potted seedlings of Plukenetia volubilis.A total of 7 treatments were designed with three factors, i.e., irrigation amount, irrigation mode and nitrogen fertilizer. The growth, photosynthesis and water use efficiency were analyzed. The results showed that compared with those under full irrigation, the biomass and water consumption under alternative partial root-zone irrigation were reduced by 5% and 75%, respectively, and the water use efficiency was increased by 60%. Under severe drought conditions, the root cap ratio in the nitrogen fertilizer treatment group was increased by 30%; the leaf area index, photosynthetic rate and biomass under alternative partial root-zone irrigation were reduced by 38%, 9% and 18%, respectively. It indicates that under severe drought conditions, alternative partial root-zone irrigation is not suitable to be matched with application of nitrogen fertilizer. In short, under moderate drought conditions, alternative partial root-zone irrigation could reduce transpiration and improve water use efficiency, and it is an effective water-saving irrigation technology for the plantation of P.volubilis plants.

星油藤WOX基因家族成员的鉴定及其表达谱分析

本研究利用星油藤(Plukenetia volubilis L.)转录组及基因组数据库,通过本地BLAST,筛选到了9个星油藤WOX(PvoWOX)基因家族成员,并对它们编码的蛋白质氨基酸序列、分子量和等电点等进行了预测。通过构建系统进化树,将该基因家族成员分为3个进化支,分别为远古支、中间支和WUS支;进一步对PvoWOX家族成员的基因结构和蛋白保守结构域分析发现在同一进化支中均很保守,并且家族成员均含有保守的同源异型结构域,其中WUS支的成员都含有WUS-box结构域。利用转录组数据和qRT-PCR对PvoWOX基因家族成员在星油藤不同器官中的表达谱进行了分析,结果显示9个PvoWOX基因成员具有不同的表达模式,其中WUS支和中间支成员的表达具有组织特异性,而远古支成员则在不同的器官中均有表达。因此推测PvoWOX家族成员具有功能多样性,分别参与调控星油藤不同器官的发育过程。本研究结果为进一步研究PvoWOX的生物学功能提供了帮助。

快中子辐射星油藤突变体库的构建及其突变体筛选

星油藤(Plukenetia volubilis L.)是大戟科(Euphorbiaceae)多年生木质藤本油料植物,其种子油富含多不饱和脂肪酸,其中α-亚麻酸含量高达44.2%~50.8%,被认为是开发高营养价值保健食用油的理想原料之一。但星油藤易感染由尖孢镰刀菌引起的致死性根茎基腐病,严重限制了其推广种植。且因中国星油藤品种资源单一,无法采用传统的杂交育种方法获得抗病高产的新品种。因此,星油藤研究中的当务之急是创制新的种质资源。本研究采用快中子辐射诱变星油藤种子进行新种质创制。首先探索了不同快中子辐射剂量对星油藤成苗率的影响,以确定半致死剂量。然后采用半致死剂量快中子辐射星油藤种子构建突变体库,对M1代植株的生物学及其农艺性状进行观测分析。结果表明:(1)星油藤种子的快中子辐射半致死剂量约为47.6 Gy;(2)快中子辐射抑制了星油藤M1代幼苗生长;(3)快中子辐射的星油藤植株表型变异类型丰富,具有肉眼可见表型变异的植株占M1代存活株的9.2%,其中诱变株3A423果实显著增大,种子单粒重是野生型的1.8倍;(4)采用随机扩增多态性DNA技术(Random Amplified Polymorphic DNA,RAPD)鉴定了5株具有扩增产物多态性的突变株。本研究获得的突变体材料将有助于星油藤遗传育种和功能基因组学的进一步研究。