中国梅的变异与分布研究

通过文献阅读、标本查阅及实地考察，发现了梅的一些变异类型。提出了梅的地理分布格局，对梅分布的历史迁作的探讨。种、滇、藏交界的横断山区是梅的自然分布中心，另外还有一些亚中心；在对种群数量和变异类型研究的基础上，确认梅的自然分布中心即梅的变异中心。     

Simultaneous down-regulation of DORMANCY-ASSOCIATED MADS-box6 and SOC1 during dormancy release in Japanese apricot (Prunus mume) flower buds

In temperate deciduous fruit crops such as Prunus spp., bud endodormancy is an important physiological phase affecting the timing of blooming and subsequent fruit development. Japanese apricot (Prunus mume) bears unmixed flower buds, separate from vegetative buds, that bloom slightly more than a month before vegetative bud burst. Seasonal expression of Prunus mume DORMANCY ASSOCIATED MADS-box genes (PmDAMs) has previously been analyzed only in vegetative buds, with an association between these genes and flower bud endodormancy release not yet confirmed. In this study, we performed a seasonal expression analysis of PmDAM1–6 genes in flower buds of two Japanese apricot genotypes – namely, high-chill and low-chill cultivars. The analysis revealed that PmDAM3, PmDAM5, and PmDAM6 expressions are closely associated with dormancy release in both flower and vegetative buds. In addition, a yeast two-hybrid screening demonstrated that PmDAM6 can interact in yeast with the homolog of Arabidopsis SOC1 (PmSOC1). Synchronized expression patterns were detected in PmDAM6 and PmSOC1 during dormancy release in flower buds of the two genotypes. Taken together, these results suggest that the dimer of PmDAM6 and PmSOC1 may play a role in the regulation of dormancy transition and blooming time in Japanese apricot flower buds.     

梅野生种与栽培品种的同工酶研究

对梅的野生种及果梅、花梅栽培品种的过氧化物酶、超氧化物歧化酶、α—淀粉酶及酯酶的研究结果表明,所有受试类型都有基本相似的特征酶谱。野生梅、半野生梅、单粉垂枝梅和淡晕宫粉梅较为原始,白须朱砂梅和送春梅较为进化,大羽梅最为进化,其构成十分复杂。     

利用RAPD标记鉴定和区分梅花42个宫粉型品种

 利用RAPD标记，对形态特征相似的42个宫粉型梅花品种的基因组DNA进行随机引物PCR扩增。从120个引物中筛选出21个引物，共扩增出96条谱带，其中多态性谱带68条，占扩增谱带数的70．8％ ，品种问相似系数范围为0．737～0．961。在21个引物中，7个引物扩增的谱带可区分27个品种，7个引物相互组合可区分其余的l5个品种。梅花品种RAPD指纹图谱的建立可以为品种知识产权保护提供依据。     

梅及其近缘种数量分类初探

对包括野梅、半野生梅、栽培果梅和桃、山桃、光核桃、杏、山杏、藏杏、洪平梅及李等共４１个分类运算单位（ＯＴＵ）选用３７个性状进行聚类分析。结果表明，梅种内可聚力杏梅、常绿梅、品字梅、毛梅、小梅、长梗梅、野梅、果梅等８个类群。以距离系数而论，与梅亲缘关系最近者为洪平梅、藏杏，其余依次为山杏、杏、山桃、光核桃、桃、李等。参照聚类结果、形态分类以及其它因素，提出了梅种内及若干近缘种有关分类位置的方案。     

果梅完全花与不完全花氮磷钾质量分数比较分析

果梅不完全花的形成和营养水平关系密切。为研究果梅完全花与不完全花营养水平的差异,测定并分析了4个果梅品种完全花与不完全花不同发育时期的氮磷钾质量分数。结果表明,4个果梅品种完全花中氮元素的质量分数大于不完全花中氮的质量分数,但是磷元素质量分数要比不完全花磷的质量分数低。各品种钾元素质量分数变化比较复杂,在小蕾期完全花钾的质量分数大于不完全花,而在开花期完全花钾质量分数小于不完全花钾的质量分数。各品种完全花与不完全花中氮、磷、钾质量分数在不同时期的变化趋势不相同。试验结果为研究果梅雌蕊败育提供了一定的营养学数据,也为进一步探索雌蕊败育问题的解决方案打下了基础。     

梅单瓣复瓣花的相关分子标记初探

 应用RAPD分子标记技术和SCAR 分子标记技术研究了梅单瓣花与复瓣花相关的分子标记。结果表明从34 个随机引物中筛选到一个多态性引物OPP01 , 扩增出只有单瓣花类型具有的分子量为1899 bp的DNA 特异片段, 即OPP01-DS-1899 ; 根据该序列设计大小分别为25 bp 和24bp 的一对引物SSD-1 和SSD-2 ,将RAPD 标记转为SCAR 标记, 该标记大小为1079 bp 。     

Determination of S-RNase genotypes and isolation of four novel S-RNase genes in Japanese apricot (Prunus mume Sieb. et Zucc.) native to China

Summary

Japanese apricot (Prunus mume Sieb. et Zucc.) originated in China with more than 500 cultivars. Most cultivars are self-incompatible. It is essential to identify S-genotypes for production and breeding. The S-genotypes of 17 Japanese apricot cultivars native to China were determined using the Prunus S-RNase consensus primer pair, Pru-C2 and PCE-R, which were designed from the second and third conserved regions of Prunus S-RNases, respectively. Eleven S-RNase alleles (S₁ S₂, S₇, S₁₂, S₁₄, S₁₅, S₁₈, S₂₀, S₂₂, S₂₃ and S₂₆) and four new S-RNase alleles (S₃₀, S₃₁, S₃₂ and S₃₃) with GenBank Accession Numbers JN232975, JN232976, JN232977, JN232978 were identified. Furthermore, the S-genotypes of four Japanese apricot cultivars were confirmed by field-testing for cross-pollination. The results of this study enrich the information available on S-genotypes in Japanese apricot and provide a reasonable basis for the appropriate arrangement of pollination trees in orchard practice.     

果梅基因组DNA提取方法的比较及ISSR分析

以果梅品种鸳鸯梅、皇后梅和肖山选的幼嫩叶片为试材,提取果梅的DNA.针对果梅组织细胞体内含有较多的酚类、糖类及萜类等次生代谢物质的特点,采用传统的CTAB法、改良的CTAB法和改良的SDS法提取果梅基因组DNA,并比较其提取效果.结果表明:改良的CTAB法可获得高质量、高得率的基因组DNA,OD260/280比值在1.80左右.通过基因组DlNA-ISSR分析,完全满足试验要求.并进一步对改良的CTAB法的关键步骤作出具体的分析讨论.     

正交设计优化果梅ISSR反应体系

以果梅(PrunusmumeSieb.etZucc.)品种鸳鸯梅为试材,采用改良的CTAB法提取果梅嫩叶DNA,利用正交设计L16(45)探讨Mg2+、dNTPs、引物、TaqDNA聚合酶及模板DNA用量对果梅ISSR-PCR反应的影响,正交试验的结果采用直观分析和方差分析相结合。建立了果梅的ISSR-PCR优化反应体系,在20μL反应体系中含2μL10×Buffer,2.5mmol·L-1Mg2+,0.2mmol·L-1dNTPs,0.32μmol·L-1引物,20~80ng模板DNA,0.75UTaqDNA聚合酶。在此基础上探讨了引物UBC840的最适退火温度、最佳循环次数及延伸时间,引物UBC840的最适退火温度为50.6℃。应用该优化反应体系,用2个不同引物对19份果梅资源DNA进行ISSR-PCR扩增,结果显示优化的反应体系具有较高的稳定性。     

采后处理对青梅果实的生理和品质的影响

测定了青梅采后室温贮藏下生理和品质的变化 ,研究了采后处理对梅果室温和冷藏后转入常温的贮藏效果。结果表明 ,采后果肉急速软化 ,可滴定酸迅速下降。各处理对青梅果实的保鲜效果以乙烯吸收剂处理效果最好 ,其次是GA3处理。CaCl2 处理浓度以 2 %为宜 ,热空气处理的时间不能超过 2d     

Development of SCAR markers to differentiate between mume (Prunus mume Sieb. et Zucc.) and apricot (P. armeniaca L.)

Summary

Mume (Prunus mume Sieb. et Zucc.) and apricot (P. armeniaca L.) are similar in fruit and tree morphology, and exhibit high cross- and graft-compatibility with each other. It is therefore difficult to differentiate mume and apricot cultivars on the basis of morphological and phenotypical characteristics. Molecular markers were developed to differentiate nine mume from ten apricot cultivars. Four dominant, random amplified polymorphic DNA (RAPD) markers that can discriminate between mume and apricot cultivars (designated OPA15₆₂₈, OPO10₅₅₀, OPO20₂₅₉, and OPU03₄₁₅) were identified from 21 decamer primers. Two RAPD markers (OPO10₅₅₀ and OPU03₄₁₅) were developed into dominant sequence-characterised amplified region (SCAR) markers (SCO10 and SCU03). These SCAR markers could differentiate between all mume and apricot cultivars.     

Fruit set after self-pollination at different floral stages and its relation to pollen-tube growth and stylar S-RNase content in Japanese apricot (Prunus mume Sieb. et Zucc.)

Summary

To investigate fruit set after self-pollination at different floral stages, and its relationship to the S-RNase content of the style in Japanese apricot, which exhibits gametophytic self-incompatibility (GSI), the cultivar ‘Xiyeqing’ was selfand cross-pollinated at –6, –4, –2, 0 and +2 d after anthesis (DAA). At –6 and –4 DAA, the percentage fruit set was low, suggesting that the propensity to seed set was weak during this period. At –2 DAA, the percentage fruit set, after self-pollination, reached a maximum of 5.97%. Thus, the effective time of self-pollination to obtain inbred seed was –2 DAA. Soluble protein extracts of styles at each floral stage were subjected to iso-electric focussing. The results showed that S-RNase began to be synthesized from –6 DAA, reached its maximum expression 2 – 3 d before anthesis, and was degraded slowly after anthesis. The number of pollen-tubes arriving at the stylar base, as detected by fluorescence microscopy, varied at –2, 0, and +2 DAA. The number of pollen-tubes arriving at the stylar base, and the percentage fruit set after self-pollination, exhibited a positive correlation (r = 0.8615; P = 0.1), while the S-RNase content per style showed a negative relationship to fruit set percentage (r = –0.9640; P = 0.01), and to the number of pollen tubes arriving at the stylar base (r = –0.9380; P = 0.01) during this period. This implied that the S-RNase content in the style was mainly responsible for the low percentage fruit set and the low number of pollen-tubes arriving at the stylar base after self-pollination.     

我国果梅品种资源若干果实性状的数量分布及其评价标准探讨

首次对我国(包括台湾)果梅108个品种果实的单果重、可溶性固形物含量、总酸含量、可食率及鲜核重等5个主要品质性状的数量分布进行了分析。结果表明,单果重平均为19.58g±6.24g,集中分布在15.01～20.00g与20.01～25.00g之间;可溶性固形物含量平均为7.44%±1.13%,大多数分布在6.01%～7.00%与7.01%～8.00%的偏低范围内;总酸含量平均为4.74%±0.95%,绝大部分品种资源分布在3.01%～7.00%之间;可食率的平均值为87.97±3.40%,在85%以上的品种数占80.36%;鲜核重平均为2.23g±0.61g,大多数分布在1.51～2.00g和2.01～2.50g之间。首次提出了这些性状的评价标准,从而为果梅资源的研究利用及育种目标的制定提供科学依据。     

气调包装和乙烯吸收剂对梅果叶绿素含量、叶绿素酶活性与乙烯释放的影响

研究在25℃下,气调包装和乙烯吸收剂处理对青梅果实采后叶绿素含量、叶绿素酶活性和乙烯释放量的影响及它们之间的关系。结果表明:2个处理均能抑制果实乙烯释放和叶绿素酶活性上升,延缓果实叶绿素含量降低,以气调包装效果更佳。对乙烯吸收剂处理的果实进行相关性分析,其内源乙烯含量与叶绿素酶活性呈显著正相关(R=0.8204),而叶绿素酶活性与叶绿素含量呈显著负相关(R=-0.8990)。     

青梅果实的采后成熟特性和肉质变化

研究了２０℃,相对湿度９３％条件下青梅果实的采后成熟特性和肉质变化,结果表明,青梅果实采后呼吸活性和乙烯生成量随着成熟作用的进展而加大,乙烯生成量极高,在呼吸类型上属于跃变型果实;果皮急速黄化,果肉急速软化,主要原因在于多聚半乳糖醛酸酶,果胶甲酯酶活性的增大,导致水溶性果胶含量上升和盐酸可溶性果胶含量的下降。     

H_2O_2在外源GA_4解除果梅季节性休眠中的信号作用

以GA_4处理的果梅休眠芽和转PmRGL2基因杨树叶片为材料,通过测定H_2O_2含量、抗氧化酶类活性及其编码基因和信号转导相关基因表达的变化,分析了H_2O_2在外源GA_4解除果梅休眠中的信号作用。结果表明:GA_4处理的果梅花芽的萌芽率显著高于对照,且H_2O_2含量在休眠解除时达到峰值,信号转导相关基因表达发生规律性变化;‘桃形梅’和‘丰后’的需冷量分别为574 CH(低温小时数Chilling hours)和1 108 CH,休眠解除前后,两品种叶芽中的H_2O_2含量没有显著差异,但需冷量低的‘桃形梅’具有更高的抗氧化酶类活性;转Pm RGL2杨树中NADPHoxi下调表达,有利于使H_2O_2含量维持在较低水平,并对赤霉素合成及信号转导相关基因的表达产生影响,而抗氧化酶类活性及其编码基因的表达量上升。推测GA_4通过调控抗氧化酶类活性而影响H_2O_2含量的变化,并引起上下游多种信号相关基因表达水平的变化,最终对休眠解除起作用。     

Effects of bud scales and gibberellins on dormancy of in vitro cultured Japanese pear leaf buds

Leaf buds of Japanese pear were collected in early June and early November and regarded as summer and winter dormant buds, respectively. Bud explants with and without scales were prepared from each of them, and cultured in vitro for 75 days at 25°C with 14 h photoperiod, on a medium either without growth regulators, or supplied with BA and GAs (GA₃ and GA₄₊₇), singly or in combination.When either BA or GA₄₊₇ was contained in the medium, bud expansion occurred. Thereafter, summer dormant buds grew into shoots in the presence of BA, while winter dormant buds, although they swelled profusely, remained in a rosette. In the presence of BA, GA₄₊₇ markedly stimulated shoot elongation of summer dormant buds, but GA₃ did not. In winter dormant buds, GA₄₊₇ not only failed to stimulate shoot elongation, but also interfered with the BA-induced swelling described above.The presence of bud scales delayed expansion of summer dormant buds, while it had little effect on winter dormant buds. The delaying effect of scales on expansion of summer buds was effectively removed by application of GA₄₊₇ to the medium.     

内源多胺含量对不同杏品种花芽分化及开花期的影响

以"银香白""早熟黑叶杏""串枝红"3个杏品种为试材,观察了杏花芽分化和开花规律,研究了在花芽分化过程中内源多胺(PAs)的含量变化,以期为杏丰产栽培管理提供参考依据。结果表明:在花芽分化期和开花期,3个品种的内源腐胺(Put)和亚精胺(Spd)含量呈规律性变化,均呈先下降后升高的趋势;而精胺(Spm)含量变化相对复杂,未呈现一定的规律。从花芽分化期到花芽露瓣期,3个品种的内源PAs含量呈高低起伏的变化,并在初花期均有一个最高峰,"银香白""早熟黑叶杏""串枝红"内源PAs含量分别为5 747.2、3 048.0、2 433.6nmol·g^-1FW。内源PAs含量对杏花芽分化和成花具有一定的影响,且高水平的Put和Spd有利于杏花芽分化的启动和成花。