'Liaoning 2' is a dwarf walnut variety bred by Chinese scientists through artificial hybridization, but little is known about its dwarfing mechanism. In this study, the dwarfing mechanism of 'Liaoning 2' is discussed through the comparison of biological characteristics, genomics and the expression of growth-related gene JrGAI,with a growth normally, closely related(half-sib families) variety of 'Liaoning 1' as control. By observing the phenology and tree phenotypes, it was found that there was no significant difference in phenological phase between 'Liaoning 1' and 'Liaoning 2', but 'Liaoning 2' was obviously dwarf, the height, crown and trunk diameter were smaller, the average length of internode reduced significantly, but there was no significant difference in the number of development branch internode. The dwarf phenotype of 'Liaoning 2' is mainly caused by inter-shortening. The qRT-PCR technique was performed to analyze the expression of GA negative regulation gene JrGAI and the results showed that during the shoot development, the expression of JrGAI gene exhibited decreasing expression in the shoot rapid growing period in both varieties and the decline in 'Liaoning 1' was remarkably reduced. The SSR analysis with 25 pairs of primers showed that SSR loci of two varieties were different, especially the homozygosity of 'Liaoning 2' SSR loci was higher. It is concluded that different expressions of JrGAI gene and homozygosity of SSR loci could be important internal reasons of dwarf phenotype of 'Liaoning 2'.

To obtain high-quality DNA suitable for methylation-sensitive amplification polymorphism (MSAP), analysis, the mature cotyledon and tissue cultured cotyledon of walnut cultivar‘Liaoning-1’were used as the testing materials in the research of DNA isolation by 3 methods (SDS, high salt CTAB and modified high salt CTAB) and the mature leaf tissue was taken as the control. The concentration and intactness of the extracted DNA were determined using a spectrometer and by electrophoresis in 0.8% (w/v) agarose gels against standard solutions of lambda DNA. High quality DNA was extracted from leaf tissues using the high salt CTAB method and the modified high salt CTAB method. No detectable DNA was extracted from the mature cotyledon and cultured cotyledon using SDS method. The DNA with high quality but little quantity was extracted from the mature cotyledon but not the extract cultured cotyledon using the high salt CTAB method. The DNA with high quantity and quality suitable for MSAP analysis from both mature cotyledon and cultured cotyledon was extracted using the modified high salt CTAB method. The DNA extraction method of walnut cotyledon suitable for MSAP analysis was established, which could lay foundation for downstream molecular biology experiment and provide a reference to the polysaccharide removal research in DNA extraction procedure.

目的 筛选云南甜龙竹和黄竹种子最佳表面灭菌条件，研究其萌发特性。 方法 筛选NaClO（2%、3%、4%）与HgCl₂（0.01%、0.1%）最佳消毒浓度组合；采用流水冲洗时间（6、12、18 h）、2%NaClO浸泡时间（5、10、15 min）和0.1%HgCl₂浸泡时间（5、10、15 min），设计正交试验实验，探讨2种竹种最佳表面灭菌处理的时间组合，并对竹种分别在滤纸、MS培养基以及经3 mg·L^-1 GA₃浸泡后在MS培养基上的发芽率进行了探讨。 结果 NaClO、HgCl₂最佳消毒浓度组合为2%NaClO+0.1%HgCl₂；2种竹种最佳表面灭菌时间组合均为：流水冲洗6 h、2%NaClO浸泡10 min、0.1%HgCl₂浸泡15 min，经此处理后云南甜龙竹和黄竹的发芽率分别为84.4%、72.2%，污染率分别为18.7%、29.6%。不同处理种子萌发率差异t检验结果显示：2种竹子种子是否经过3 mg·L^-1 GA₃浸泡，对其在MS培养基上的发芽率无显著影响，但种子在MS培养基上的发芽率显著高于滤纸上的发芽率。经相同处理黄竹的发芽率均低于云南甜龙竹。 结论 云南甜龙竹、黄竹最佳表面灭菌组合均为：流水冲洗6 h、2%NaClO浸泡10 min、0.1%HgCl₂浸泡15 min；3 mg·L^-1 GA₃浸泡处理对云南甜龙竹和黄竹种子在MS培养基上的发芽率无显著影响，但MS培养基上种子的发芽率显著高于其在滤纸上的发芽率。

目的 揭示屏边空竹的发笋、退笋和幼竹生长规律。 方法 定点观测了30丛屏边空竹周年的出笋、退笋、秆高及地径生长数据，运用SPSS软件分析评价了不同季节出笋及幼竹生长规律。 结果 （1）屏边空竹笋期历时9个月左右（从9月至次年5月），根据出笋量的差异可分为初期、盛期和末期，春季最多而夏季最少；其中5丛（16.67%）每季出笋，具有四季发笋的习性。（2）退笋率随着笋期逐渐增加，在出笋末期达到最高，为87.76%。（3）笋-幼竹高生长约130 d完成，平均秆高达6.36 m；呈现"慢-快-慢"的生长规律，生长曲线可用三次曲线方程描述：H=0.806-0.029t+0.001t²-5.894×10^-6t³，R²=0.980。（4）地径的生长历时16 d左右，平均地径为18.50 mm，也呈现"慢-快-慢"的生长规律。 结论 屏边空竹发笋期长约9个月，具有四季发笋的习性，但各季节出笋量差异显著；秆高和地径呈现"慢-快-慢"的生长规律。

目的 利用荧光定量PCR(qRT-PCR)和表达分析软件筛选适用于巨龙竹秆形发育研究的qRT-PCR的稳定内参基因。 方法 应用常规PCR和qRT-PCR, 分析EF-1α、GAPDH、Actin、Tubulin、TIP-41、PP2A共6个内参基因在不同秆形巨龙竹("通直型"和"弯曲型")竹笋3个不同发育时期的表达情况。利用GeNorm、NormFinder软件对各内参基因的表达稳定性进行评估; 以筛选的内参基因对巨龙竹木质素合成中的PTAL基因的表达量进行定量分析, 验证所筛选内参基因的有效性。 结果 PCR和qRT-PCR的结果表明, 6个候选内参基因PCR目的片段电泳条带单一, 熔解曲线具有明显的单一峰。内参基因Actin、EF-1α、GAPDH的稳定性和相关性表现最佳; 以它们为内参, 对茎秆发育过程中PTAL基因进行定量分析, 结果显示它们均具有高效性。 结论 Actin、EF-1α、GAPDH可以作为巨龙竹秆形发育研究中目的基因定量分析的内参基因。为进一步分析巨龙竹秆形发育过程中关键基因表达量的变化提供研究基础。