‘富士’苹果痘斑病与Ca营养、分布和定位

【目的】研究苹果痘斑病果实和健康果实不同部位Ca、K和Mg含量及离子微区分布,分析Ca定位与痘斑病发生之间的关系,探讨果实产生痘斑病的主要原因。【方法】以‘短枝富士’苹果(Malus domestica cv.Spur Fuji)为材料,用原子吸收法测定患痘斑病果实(简称病果)与健康果实(简称健果)的顶、中、底部果皮组织中Ca、K和Mg含量。同时,用X射线能谱仪分析果皮和果肉组织中Ca、K和Mg的微区分布,并观察Ca在亚细胞水平上的分布规律。【结果】病果的果皮中Ca含量显著低于健果,而K和Mg含量与健果无显著差别。X射线微区分析证明,健果果皮中Ca和K的X射线峰值显著高于病果的,健果果肉中Ca峰值显著高于病果的,K的峰值相反,但病斑区域K峰值极高。在健果中,Ca颗粒大量存在于果皮或果肉的液泡中,且分布均匀,但在病果中,Ca颗粒分布显著减少,尤其是在病斑区域的果皮细胞中,大量Ca颗粒出现在内陷的液泡膜之外,且其细胞形状不规则,内含物减少,内部形成大小不同的囊泡。【结论】病果的果皮组织中Ca含量明显低于健果的,病斑区果肉中积累大量的K。果皮细胞内Ca外泄,液泡内Ca明显减少。这些揭示细胞内Ca参与苹果果实痘斑病的发生。

Effects of Ca2+concentrations on accumulations of mineral elements in the components of Pteroceltis tatarinowii

The bark of Pteroceltis tatarinowii is a raw material for manufacturing Xuan Paper. The effects of Ca2+ concentrations on the accumulation of mineral elements in the bark, leaf and root of Pteroceltis tatarinowii were studied under controlled condi-tions. The types of Hoagland nutrient solution with three Ca2+ concentrations levels (200, 400 and 600 靏g-1) and a control (without Ca2+) were designed to culture Pteroceltis tatarinowii. After 6 months, contents of seven mineral elements including Ca, K, Mg, Mn, Zn, Cu and Na in the root, leaf and bark were analyzed. The results indicated that Ca accumulations content in the root, leaf and bark had positively relation with Ca2+ concentrations (200, 400, 600 靏g-1), and the order of the Ca content in the three components was root】leaf】bark. Ca content in the root treated with 600 靏g-1 Ca2+ concentrations was 5.5 times as high as that of the control, and about 1.4 times as high as that of the root treated in 200 and 400 靏/g Ca2+ concentrations respectively. On the contrary, K and Mg contents in the root, leaf and bark were negatively related to Ca2+ concentrations, especially in the bark, and their accumulation trend followed the order of leaf】root】bark. K content in the bark treated with 600 靏g-1 Ca2+ con-centrations was 39.3% of that of the control, and was 79.0% and 91.8% of that of the bark treated with 200 靏g-1 and 400靏g-1 Ca2+ concentrations respectively; Mg content in the bark treated with 600 靏g-1 Ca2+ concentrations was 23.4% of that of the control, and was 27.1% and 35.4% of that of the bark treated with 200 and 400 靏g-1 Ca2+ concentrations respectively. Com-pared with the control, the general tendency of Mn, Zn and Cu content decreased with increasing of Ca2+ concentrations and their contents were in the order: root】leaf】bark. Based on the results of this study, the experiment has been useful for providing academic bases in improving the bark quality of Pteroceltis tatarinowii on non-limestone soil.

辣椒果实钙吸收累积的基因型差异及其生理特征

采用砂培试验研究了 16个辣椒品种对Ca吸收累积的基因型差异和产生差异的生理特征。结果表明 ,在不同供Ca水平下 ,辣椒果实Ca含量的品种间差异明显 ,按供Ca水平与果实Ca累积关系 ,将其分为 :不敏感型 (低Ca时果实Ca降幅 <10 % ,高Ca时变幅± 5 % )、敏感型 (低Ca时果实Ca降幅 >10 % ,高Ca时降幅 >10 % )和增Ca潜力型 (果实Ca随供Ca水平提高而提高 ,增幅 >10 % )三个基因型。比较讨论了三类基因型品种在根系形态特征、叶片蒸腾速率和CAT活性的差异 ,说明辣椒吸收养分及适应能力、蒸腾速率。