The objective of this study was to determine how xanthophyll cycle-dependent thermal dissipation and the antioxidant system in the peel of apple fruit respond to the natural light exposure within the tree canopy. Fruit from exterior and interior canopies of both mature 'Gala' and 'Smoothee' apple trees were sampled at noon and/or predawn to measure chlorophyll fluorescence, xanthophyll cycle pool size and composition, and enzymatic and non-enzymatic antioxidants. Compared with the shaded side, the sun-exposed peel of the fruit had more excess absorbed photon flux density (PFD) as a result of a lower photosystem II operating efficiency and a higher incident PFD at noon. The efficiency of excitation transfer was lower in the sun-exposed peel than in the shaded peel, indicative of higher thermal dissipation. The sun-exposed peel had a larger xanthophyll cycle pool size and a higher conversion state. It also had higher activities of ascorbate peroxidase, monodehydroascorbate reductase, dehydroascorbate reductase, and glutathione reductase, and a larger size and a higher reduction state of the ascorbate pool and the glutathione pool. However, catalase activity was lower in the sun-exposed peel than in the shaded peel. Superoxide dismutase did not show significant trend with regard to fruit peel type or position in the canopy. We conclude that both the xanthophyll cycle and the ascorbate/glutathione pathway in the apple fruit peel are acclimated to the prevailing light exposure within the tree canopy to meet the respective needs for dissipating excess absorbed PFD and detoxifying reactive oxygen species.

介绍了一种从木本植物组织中获得高质量RNA 的快速、简单和高效的核酸提取方法。该方法是基于核酸的二氧化硅捕获，避免了使用苯酚、氯仿等有机溶剂。利用该方法从樱桃组织中提取的总RNA 用RT 2PCR技术检测PDV，PNRSV 均获得成功。从感病植株的一年生枝的叶片、韧皮部及芽组织中扩增出了预期的目的片段，即172和449bp，而健康组织中无此扩增带。该法提取的总RNA用于RT 2PCR技术检测，其敏感性至少与商业出售的Qiagen RNeasy提取试剂盒相当，但简单经济。

研究了影响山杏下胚轴再生的有关因素，首次获得了山杏下胚轴再生植株。结果表明：在附加TDZ2mg/L、AA0.5mg/L的改良MS培养基（1/2 NH4NO3）上愈伤组织诱导率（100%）和再生频率（37.5%）均最高，TDZ效果优于6-BA，不定梢在改良MS+IBA0.2mg/L培养基上生根率为75.8%。

Bench-grafted 'Fuji/M.26' apple (Malus domestica Borkh.) trees received a constant nitrogen (N) supply (10.7mM) from bud break to the end of June, and were then fertigated with 0, 5, 10, 15 or 20mM N in a modified Hoagland's solution for 2 months during the summer. In mid-October, half of the trees fertigated at each N concentration were sprayed twice with 3% urea, whereas the remaining trees served as controls. All trees were harvested after natural leaf fall and were stored at 2℃. Five trees from each of the N treatment combinations were destructively sampled during dormancy to determine the composition of N and total nonstructural carbohydrates (TNC). As the N supply from fertigation increased, amounts of N in both free amino acids and proteins increased, whereas C/N ratios decreased. Foliar urea applications in the fall significantly increased amounts of N in both free amino acids and proteins, but decreased their C/N ratios. Arginine, the most abundant amino acid in both free amino acids and in proteins, accounted for an increasing proportion of N in free amino acids and proteins with increasingNsupply from fertigation or foliar urea application. The ratio of proteinNto free amino acidNdecreased from about 27.1 to 3.2 as N supply from fertigation increased from 0 to 20mM, and decreased further to 3.0 in response to foliar urea applications in the fall. Concentrations of glucose, fructose, sucrose and TNC decreased as theNsupply from fertigation increased, whereas concentrations of sorbitol and starch remained relatively unchanged. Foliar urea applications decreased the concentration of eachTNCcomponent and theTNCconcentration in each N fertigation treatment. A negative linear relationship was found between carbon in TNC and N in proteins and free amino acids. The sum of carbon in TNC, proteins and free amino acids remained constant in response to N supply from fertigation. However, foliar urea applications decreased the sum of carbon in proteins, free amino acids and TNC because about 21% of the decrease in TNC carbonwas not recovered in free amino acids or proteins.Young apple trees storeNand carbon dynamically in response to N supply. As N supply increases, an increasing proportion of N is found in the form of free amino acids, which have a low carbon cost, although proteins remain the main form of N storage. Furthermore, part of the carbon from TNC is incorporated into amino acids and proteins, proteins, decreasing the carbon stored as TNC and increasing the carbon stored as amino acids and proteins.

蔷薇科植物中，与山梨醇代谢相关的酶主要有：62磷酸山梨醇脱氢酶、山梨醇脱氢酶和山梨醇氧化酶。综述了近些年来国内外关于这几种酶的研究进展，涉及的内容有：酶的性质与作用、酶的活性变化与转录的关系，及其在生物技术方面的研究成果，并对今后的研究工作进行了展望。