不同培养基及添加物对金线莲生长量的影响

以金线莲为材料,研究在不同培养基中添加不同量的香蕉和马铃薯对金线莲生长量的影响。结果表明:100%MS大量+3%蔗糖培养基是最利于金线莲生长量积累的培养基。在相同培养基中,添加香蕉比添加马铃薯更有利于金线莲生长量的积累。金线莲生长量积累的最佳培养基是:100%MS大量+3%蔗糖+20.0%香蕉。     

刺梨果实主要抗氧化组分对机械伤及 UV-B 胁迫的响应

 以‘贵农5 号’刺梨为材料,研究了果实发育过程中主要抗氧化组分对机械伤及UV-B 胁迫的响应。结果表明：机械伤和UV-B 处理均可诱导刺梨果实中H2O2 等自由基的产生,并促使膜脂过氧化水平增加;但抗氧化系统对两种胁迫的响应模式不尽相同：机械伤胁迫下抗氧化酶POD、SOD 以及非酶组分AsA、GSH 均受快速产生的H2O2 等自由基诱导,表现出快速应激响应;之后这两种抗氧化酶呈现出逐渐降低的趋势,而AsA 和GSH 则一直保持在较高水平。在UV-B 处理中,需要较长时间额外增加UV-B辐射才会有效增加成熟果实中SOD、AsA 及GSH 等组分的活性或积累;而在减弱紫外处理时,SOD、POD和GSH 的变化均表现出前期升高后期回落的趋势。机械伤和UV-B 胁迫下,CAT 和APX 等酶只是间或或根本无法检测到活性。总体上看,POD + SOD 以及AsA + GSH 的共同作用是刺梨果实在这两种胁迫下抗氧化反应的主要机制。     

刺梨及部分近缘种形态学性状和RAPD标记分析

 通过36个形态学性状和29个引物RAPD扩增获得的分子标记，探索刺梨及部分近缘种的亲缘关系。结果表明，普通刺梨所有基因型之间的亲缘关系较近，而与其余种类相对较远；无籽刺梨与贵州缫丝花的遗传距离较近，形态学和RAPD聚类分析都显示很近的亲缘关系；尽管两类遗传距离的排序和聚类分析有一定差异，但Mantel相关性检测表现出显著相关性(r=0.6122，P<0.01)。还就无籽刺梨的可能来源进行了讨论。     

柿胚与果实发育相关性的研究

以甜柿品种卡迟莎和涩柿品种高安方柿为材料,采用常规石蜡切片法及SAS统计分析法,对果实发育及其与胚发育相关性进行了研究。结果表明:果实横切面从外到内是表皮层、石细胞层、中果皮及内果皮组成的果肉组织。表皮外层主要表现为垂周分裂和平周生长;石细胞是厚壁组织中典型的短石细胞。果实、种子发育与胚发育有着密切的关系,果径、种子长与胚长存在高度的正相关性,各相关方程的相关系数均达极显著水平。     

荔枝胚败育差异表达基因cDNA 片段的克隆及序列分析

 利用抑制消减杂交(Suppressive subtraction hybridization , SSH) 克隆荔枝败育胚的差异表达基因cDNA 片段。分别以荔枝‘桂味’正常发育胚为driver (驱赶子) , 败育胚为tester (检测子) , 建立差异表达cDNA 文库, 代表桂味败育胚特异表达的cDNA。经Virtual Northern 检测, 在桂味正常发育胚/ 败育胚差异表达cDNA 文库中得到3 个阳性克隆, 序列分析表明这3 个克隆对应的两个序列在荔枝中为首次报道。     

Reciprocal difference of interspecific hybridization between three different colours of Iris dichotoma and I. domestica

Previously, we found that reciprocal F₁ hybrids of purple-flowered Iris dichotoma and I. domestica were different. To further characterize this reciprocal difference, we carried out reciprocal crosses between three different colours of I. dichotoma and I. domestica. Morphological and cytological characters of F₁ hybrids of six interspecific crosses between three different colours of I. dichotoma and I. domestica (three direct and their three reciprocals) were evaluated. The results showed that the fruit-setting rates of three different colours of I. dichotoma as female and I. domestica as male were lower than reciprocal cross combinations, but their seed germination rates were significantly higher than reciprocal ones. Reciprocal differences of F₁ hybrids were observed for most morphological characters. The F₁ hybrids of three different colours of I. dichotoma as female were totally different from their parents; however, the F₁ hybrids of I. domestica as female were extremely similar to the mother. The six interspecific hybrids had the same chromosome number (2n = 32) as their parents. Reciprocal differences were detected for karyotype. Parents’ and F₁ hybrids’ karyotypes focused on 1A to 2B. In these cases, the direction of the cross must be kept in mind in order to improve the efficacy of future breeding programmes.     

大白菜与结球甘蓝杂交获得异源三倍体及其生殖特性的研究

 为创制大白菜—结球甘蓝异附加系、异代换系、易位系, 利用四倍体大白菜(AAAA, 2n =4x= 40) 为母本与二倍体结球甘蓝(CC, 2n = 2x = 18) 杂交, 采用蕾期去雄授粉、子房培养结合胚珠培养的方法, 获得了异源三倍体(2n =3x = 29, AAC) 杂交后代。该杂交种总体形态偏近于大白菜, 但生长势极强, 株高(开花期) 2 m; 花粉整齐度、花粉生活力都明显低于二倍体大白菜; 减数分裂行为复杂, 终变期除二价体和单价体外, 还有三价体等联会形式; 与二倍体大白菜回交的平均结籽率为3.19%。     

夏蜡梅与美国蜡梅属间杂交障碍的组织学机理

 以夏蜡梅属夏蜡梅（Sinocalycanthus chinensis）和美国蜡梅属美国蜡梅变种光叶红蜡梅（Calycanthus floridus var. oblongifolius）为试验材料进行属间杂交,通过荧光镜检观察花粉在柱头上的附着和萌发以及利用石蜡切片观察杂种胚发育情况,探讨其杂交障碍机制。结果表明：不论正反交,花粉均能在柱头上粘附36 h到达胚囊,表明花粉萌发和花粉管生长阶段不存在杂交障碍。杂种胚发育观察结果表明,无论正反交均可以实现双受精,但结实率极低,说明属间杂交存在受精后障碍,且正反交杂交障碍机制有所不同：当以夏蜡梅为母本时,杂交障碍主要由受精后杂种胚早期的不正常解体造成;而当以光叶红蜡梅为母本时,杂交障碍主要由母本雌蕊较高比例的发育异常和杂种胚的早期败育共同引起。 、萌发并生长到达胚囊;以夏蜡梅为母本时父本花粉管生长进程较以光叶红蜡梅为母本时更加一致,大部分花粉管在授粉后     

An investigation of the relationship between reproductive growth and yield loss in hazelnut

This study was carried out in Samsun during a 2-year period to examine the relationship between reproductive and yield loses in the ‘Tombul’ and ‘Palaz’ hazelnut cultivars. In hazelnuts, male and female flowering occur in winter after the breaking of inflorescence dormancy. In the present study, growth of the ovary of the hazelnut started in April and continued until mid-June. At the time of flowering the ovary did not form. The ovule growth showed a rapid increase at the end of June. Change in the diameter of the ovary and ovule with time showed a simple sigmoid growth curve. Fertilization occurred during the period between mid-May and the beginning of June, namely, 3.5–5 months after pollination. At this time, the diameter of the nut was 9.54 mm. Twin kernel was not observed. The ratio of double kernels was close to zero. The time period from fertilization to harvest was 89 days in 1997 and 96 days in 1998 for Tombul cultivar. For the Palaz, this period was 84 days in 1997 and 86 days in 1998. The rate of pistillate flower clusters which dropped in April–May was more than those dropped in June–August.