[目的]筛选适宜的银杏树形,为银杏优质、丰产栽培提供参考.[方法]2019年4—9月,以开心形和主干分层形2种树形的银杏植株为研究对象,使用Yaxin-1102G光合仪测定2种树形银杏的光合作用相关参数,采用95％乙醇浸提法测定叶片叶绿素含量,分别采用蒽酮比色法、考马斯亮蓝法和索氏提取法测定银杏种仁的可溶性糖、淀粉、蛋白质和油脂含量,对2种树形植株的光合特性、种仁品质及种实产量进行比较分析.[结果]在2019年6月4日06:00—18:00和2019年4—9月各月份,总体上开心形银杏植株的净光合速率、蒸腾速率、气孔导度、胞间CO2浓度均大于主干分层形植株.2种树形银杏植株叶片的叶绿素a、叶绿素b含量均呈先升高、后降低的变化趋势,开心形银杏植株的叶绿素含量高于主干分层形植株.开心形银杏植株种仁的可溶性糖、油脂、淀粉、可溶性蛋白等内含物含量均高于主干分层形植株,但开心形银杏植株的种实产量低于主干分层形植株.[结论]开心形银杏树形结构较为合理,具有叶片叶绿素含量高、光合特性好、种仁品质优、种实产量稍低的特点,可通过适当修剪,培养结果枝,达到增产的目的;主干分层形植株的主枝多,叶片叶绿素含量低,光合特性差,种仁品质差,种实产量较高,可通过疏除过密枝条、加强肥水管理,促进优质银杏种实生产.

SBP转录因子在植物生长发育、信号转导、胁迫应答等方面起着重要的调控作用,由SBP基因家族基因编码.为探究银杏SBP基因家族的特征及表达模式,采用高通量测序技术对银杏的叶、花芽和胚珠进行转录组测序,鉴定SBP基因家族成员,并进行基因定位、miRNA 156靶位点预测、进化关系以及表达模式的分析.本研究共鉴定到15个银杏SBP基因家族成员,该基因家族在染色体上分布较分散,编码产物长度差异较大,其中有5个成员具有miRNA156靶位点.蛋白保守基序分析显示,除GbSBP5、GbSBP12、GbSBP14不具有完整的SBP保守结构域外,其余成员编码蛋白均具有SBP保守结构域(包括2个锌指结构和1个核定位信号).聚类分析表明,银杏SBP基因家族成员可以分为8个亚组.表达分析显示,SBP基因家族成员在银杏叶、花芽、胚珠中的表达水平存在一定差异,且在叶和花芽的不同发育时期呈现出不同的表达模式.本研究为银杏SBP基因家族的功能分析奠定了基础,并为银杏分子育种提供了一定的理论依据.

A careful analysis was made of the variation of the main biochemistry index, such as MDA, PRO and dissolved sugars, of 3 year-old Ginkgo under flooding stress. The results show that compared to the contrast, the content of MDA in the leaves of Ginkgo did not vary obviously under flooding stress in 9 days; that being 18.7 μmol/g, it changed at the tenth day compared to the contrast, being 7.2 μmol/g; that the content of PRO in the leaves of Ginkgo was obviously increased compared to the contrast at the eighth day after flooding stress; that the content of dissolved sugars in the leaves of Ginkgo was becoming more, reaching 32.9 mg/g at the ninth day; and that the activity of SOD in 5 days under flooding stress increased quickly to 854.6 U/g, then it dropped at the sixth, to (78.8 )U/g at the eleventh, being much lower than that of the contrast.

Callus inducement and adventitious bud differentiation in Pueraria lobata were carried out by culturing on MS with hormones NAA, 6-BA, and IAA. Results indicated that young leaves, stem fragments and tip buds could all be induced into callus under suitable hormones, but the inducement rate varied with different hormone combinations. The best medium for callus formation from young leaves was MS+NAA 1.0 mg/L+6-BA 1.0 mg/L, and the rate of callus formation was 75 percent; the best medium for callus formation from stem sections was MS+NAA 1.0 mg/L+6-BA 3.0 mg/L+IAA 0.2 mg/L, and the rate of callus formation was 70 percent. The rate of adventitious bud differentiation varied with the calli induced from different explants, and the adventitious buds could be induced from the calli formed from stem sections with various concentrations of 6-BA. Light was favorable for the bud differentiation, and under light conditions, the average rate of bud formation form stem sections was 66.7 percent.

以银杏幼叶为外植体,对银杏进行愈伤组织诱导和继代培养.通过正交试验设计,研究了不同浓度的3种激素配合使用对银杏愈伤组织诱导的效果,筛选出诱导银杏愈伤组织的最佳培养基:MS+3mg/LNAA+3mg/L6-BA.研究了在银杏愈伤组织继代过程中,不同浓度的4种抗氧化剂对褐变抑制的效果,筛选出最佳抗氧化剂及其浓度:10 mg/LVc.4种抗氧化剂对抑制褐变的效果如下:Vc>PVP>柠檬酸>Ac,其中,PVP的最佳浓度为1 g/L.继代过程中,光照条件对愈伤组织褐变程度有一定的影响.