铝胁迫对黄瓜种子发芽及抗氧化酶活性的影响

本试验以黄瓜品种津春2号为材料,研究了铝胁迫对黄瓜种子发芽及抗氧化酶活性的影响。结果表明,铝处理显著抑制了黄瓜种子萌发后根部的伸长,提高了根部抗坏血酸过氧化物酶（APX）、过氧化物酶（POD）、过氧化氢酶（CAT）和脱氢抗坏血酸还原酶（DHAR）活性。超氧化物歧化酶（SOD）在低浓度铝处理下活性升高,而在高浓度下降低。     

几种微生物菌剂处理下连作黄瓜的生长分析

采用盆栽法研究了4种微生物菌剂(连茬王、护根宝、金宝贝、木霉菌肥)处理对连作黄瓜生长的影响。结果表明:4种菌剂处理下连作黄瓜的各项生长指标均较对照有所提高;木霉菌肥和护根宝处理明显提高了连作黄瓜的相对生长率、净同化率、叶面积指数、群体光合势及群体生长率;连茬王处理对黄瓜叶重比及叶片厚度具有明显的促进效应。综合各菌剂对连作黄瓜地上部生长的改善效果,依次为木霉菌肥护根宝连茬王金宝贝。     

利用黄瓜远缘群体遗传连锁图谱进行始花节位定位

利用黄瓜远缘群体的分子遗传连锁图谱,对雌花节位性状进行了QTL定位。共找到8个控制雌花节位的QTL位点:ff-1、ff-2、ff-3、ff-4、ff-5、ff-6、ff-7、ff-8,分别位于LG2、LG3、LG6、LG7连锁群上,这些QTL位点对雌花节位性状表型变异贡献率分别为81.6%、81.0%、81.0%、80.0%、80.6%、81.1%、81.0%、80.7%,其中ff-1、ff-2、ff-5、ff-6、ff-7、ff-8加性效应值为正,为增效加性效应,ff-3、ff-4加性效应值为负,是减效加性效应。     

不同留芽数量对藏红花生长的影响

研究了不同留芽数量对藏红花生长的影响。结果表明:在整个生长期,不同留芽数量下的藏红花各生长阶段发生的时间差异不大。藏红花种球萌动以后,留3个侧芽的植株生长最快,留2个侧芽的植株生长最慢。在开花期,不同处理的花梗长度、花朵直径、叶片数及叶长差异不显著。随着留芽数量的增多,藏红花的柱头、雄蕊的干重增加,但各处理间没有显著差异。建议在生产中保留2～3个侧芽,以便提高柱头产量。     

三个萝卜主产区软腐病病原菌的分离与鉴定

为有效防治萝卜(Raphanus sativus L.)软腐病,提高萝卜产量和质量,从江苏徐州、浙江萧山和湖北利川3个萝卜主产区分别采集萝卜软腐病病样并进行病原菌的分离鉴定及致病力测定。通过结合菌落形态、生理生化指标测定和16S r DNA基因序列分析,确定3株病原菌属于胡萝卜果胶杆菌(Pectobacterium carotovorum)的2个亚种,其中2株为Pectobacterium carotovorum subsp.brasiliense,另1株为Pectobacterium carotovorum subsp.carotovorum。致病力测定分析表明,3株病原菌的致病力存在显著差异,随温度的升高均呈现出增强的趋势。     

黄瓜叶片衰老过程中脂滴的原位降解和液泡内降解

对黄瓜不同发育阶段叶片中的脂滴进行超微观察,以期了解衰老叶内脂滴降解的场所。结果表明,衰老叶片中部分质体小球在叶绿体内降解,降解先从小球一侧开始,向另一侧推进。衰老叶片含有胞质脂滴,有些胞质脂滴紧贴叶绿体,显示其发生与叶绿体密切相关;有些胞质脂滴与液泡密切接触,并向液泡内转运,进入液泡后发生降解。显然,黄瓜叶衰老不仅引起脂滴在液泡内降解,也引起脂滴在叶绿体内原位降解,证明液泡并不是脂滴降解的唯一场所。     

山黧豆CASase基因的克隆及RNAi载体的构建

β-腈基丙氨酸合成酶（CASase）是调控山黧豆（Lathyrus sativus）内源毒素β-ODAP合成的关键酶。本研究以山黧豆幼根RNA为模板,利用RT-PCR扩增了505 bp的山黧豆CASase基因序列;通过Gateway BP反应将扩增片段连接到入门载体构建pENTR-CASase。经测序验证后,将目的片段插入到植物表达载体构建pSGRNAi-CASase,并将其转化到农杆菌GV3101中;为进一步的遗传转化奠定了基础。     

Phytotoxicity of Cadmium in Radish and Its Effects on Growth,Yield, and Cadmium Uptake

A greenhouse experiment was conducted to study the effects of cadmium (Cd) on growth, biomass yield, and Cd uptake in three radish (Raphanus sativus L.) varieties at the Indian Institute of Horticultural Research, Bangalore, India, during 2008–2009. Plants were subjected to different Cd levels by application of cadmium nitrate [Cd (NO₃)₂] at the rates of 0, 50, 100, and 200 mg Cd kg^?1 soil. Length and fresh and dry biomass yields of shoots and roots decreased because of the phytotoxic effect of Cd. Among three varieties, Japanese White Long showed the greatest sensitivity to Cd toxicity. The accumulation of Cd in shoots and roots was greatest in Japanese White Long, which had greater bioconcentration factor values. Variety Arka Nishanth recorded lower bioconcentration factor values and greater transfer coefficient values, indicating lower Cd accumulation in root tubers in this variety. Hence, variety Arka Nishanth can be preferred in Cd-contaminated soils.     

Stimulating and toxicity effects of nickel on growth,yield, and fruit quality of cucumber supplied with different nitrogen sources

Limited information is available on biological effects of various levels of nickel (Ni) (deficiency to toxicity levels) on growth and yield of certain crops, particularly vegetables. In this sand‐culture study, we investigated the effects of four levels of Ni (0, 50, 100, and 200 μM) on growth, yield, and fruit‐quality attributes of two cucumber cultivars (Cucumis sativus L. cvs. Super Dominus and Negin) supplied with urea or NH₄NO₃ as nitrogen source. Addition of 50 μM Ni to the nutrient solution resulted in a significant increase of shoot and root dry‐matter yield of cv. Negin although this increase was greater in the urea‐fed plants than those fed with NH₄NO₃. In both cultivars, addition of 50 μM Ni increased urease activity and thereby decreased the urea concentration in the urea treatment. Addition of 100 and 200 μM Ni caused a significant decrease in root and shoot growth of cucumber although this decrease was insignificant for cv. Super Dominus in the 100 μM treatment. The highest fruit yield, total soluble solids (TSS), and fruit firmness were achieved at the 50 μM Ni treatment. Regardless of nitrogen source, Ni addition proportional to the concentration used increased leaf Ni concentration and fruit acid ascorbic concentration. The concentration of Ni required for optimum growth and yield of cucumber varied with cultivars. The level of 50 μM was sufficient for optimum growth of cv. Negin in nutrient‐solution culture while lower concentration of Ni was required for cv. Super Dominus. While the beneficial effects of sufficient levels of Ni on growth and yield of urea‐fed plants was greater than with NH₄NO₃‐fed plants, the toxic effects of Ni in these plants were also greater.     

黄瓜发芽期耐冷性与赖氨酸脱羧酶基因表达

 经15℃低温诱导，采用cDNA-AFLP技术从耐冷性强的黄瓜品种长春密刺中分离到一条特异片段，该片段在耐冷性弱的北京截头中不能被诱导，命名为cctr132。将cctr132回收测序并翻译为氨基酸序列，用blastx和blsatp程序在NCBI GenBank数据库中进行同源性检索和相似性比对，结果发现cctr132与水稻推测的类赖氨酸脱羧酶蛋白同源性为88.37%，相似性为100%，并且在CCTR132中检测到了赖氨酸脱羧酶家族推测的保守结构域PGGXGTXXE，说明黄瓜发芽期耐冷性与赖氨酸脱羧酶基因表达有关。