紫叶李叶片色素成分分析

紫叶李Prunus cerasifera是常见的园林绿化观叶树种,其叶片在整个生长季节均为紫红色。以紫叶李叶片为试验材料,利用高效液相色谱仪-二极管阵列检测器、紫外-可见分光光度计、薄层色谱分析法对紫叶李叶片的色素种类及含量进行了定性和定量分析。结果表明:紫叶李叶片内含有类胡萝卜素、叶绿素(叶绿素a为主)、矢车菊素、矮牵牛素、矢车菊素半乳糖苷、天竺葵素及其他单体酚(槲皮素、芦丁、二氢杨梅酮等)。其中,矢车菊素半乳糖苷、矢车菊素和叶绿素的共存互作是其叶片呈现紫红色的主要原因,类胡萝卜素、槲皮素、芦丁等辅助色素也起到了辅助成色的作用。     

Effects of nitrogen content on growth and hydraulic characteristics of peach （Prunus persica L.） seedlings under different soil moisture condi- tions

A pot experiment was conducted to investigate the effects of nitrogen content [N1(no fertilizer), N2(0.15 g?kg–1), and N3(0.3 g?kg–1)] on the growth and the hydraulic characteristics of peach seedlings under different soil moisture conditions(W1, W2 and W3, in which the soil water content was 45% to 55%, 60% to 70%, and 75% to 80% of the field water capacity, respectively) by using a specialized high pressure flow meter with a root chamber and a coupling, which was connected to plant organs. Leaf area and leaf hydraulic conductivity(KL) increased significantly in the seedlings because of increased soil moisture and N content. KL increased with leaf area. A linear correlation was documented between KL and leaf area. KL was higher in the morning and began to decline sharply after 16:00, at which KL declined after an initial increase. Soil moisture and N content enhanced shoot(Ks) and root(Kr) hydraulic conductivities, thereby improving the low soil moisture condition to a large extent. Ks and Kr of the seedlings were reduced by 32% and 27% respectively in N1, and by 14.7% and 9.4%, respectively in N2, and both in W1, compared with the control treatment. N3 had no significant effect on Ks and Kr under similar conditions. Linear negative correlations were observed between Kr and the excised root diameter as well as between Ks and the shoot stem diameter. The shoot-to-root ratio increased with increase in N content. The shoot-to-root ratio in N3 was increased by 14.37%, compared with N1 in W1 as well as by 12% and 4.39% in W2 and W3, respectively. Knowledge of the effects of soil moisture and N fertilizer on hydraulic characteristics and growth is important. Our results provide basic guidelines for the implementation of water-saving irrigation and fertilization management of nursery stock.     

西伯利亚杏SRAP-PCR反应体系的优化研究

以西伯利亚杏为试验材料,进行基因组DNA的提取、扩增及电泳试验。通过L16(45)正交试验,确定西伯利亚杏SRAP-PCR优化反应体系(反应体系总体积20μL):Mg2+2.0 mmol·L-1、dNTPs0.25 mmol·L-1、引物浓度1.2μmol·L-1、Taq聚合酶1.0 U、DNA模板20 ng。采用SRAP引物组合ME5/EM10,对优化的SRAP-PCR反应体系进行初步验证,24个西伯利亚杏无性系SRAP分子标记试验共扩增出谱带431条,引物扩增出23条谱带,其中338条为多态性谱带,多态百分率为78.42%。     

基于454测序的碧桃花瓣组织转录组核苷酸变异1）

通过对碧桃花瓣组织进行转录组测序,获得1556684条序列,平均读长446 bp,共计695．34 Mb数据,其中1492289条高质量序列经拼接后得到22762个重叠群。以拼接后的重叠群作为参考序列,利用SNP／InDel分析软件检测碧桃花瓣组织转录组中的核苷酸变异位点,共得到9836个SNP和1550个InDel位点。在SNP位点中,转换占62．55％、颠换占37．45％,A／G的变异最为丰富,C／G的变异最少。在InDel位点中,有34．71％的位点为单核苷酸插入、缺失突变。     

阜新低山缓丘区林农复合生态系统土壤酶活性特征

对阜新低山缓丘区大扁杏、南国梨林农复合系统构建初期土壤酶活性演化动态进行研究。结果表明,每种林农复合系统土壤酶活性都显示土壤表层高于下层。在植物生长期,过氧化氢酶、脲酶和蔗糖酶活性呈现不同的变化特征：过氧化氢酶都呈“山脊”状变化且7月活性最高。在南国梨林农复合系统中,脲酶活性呈直线增长,在9月活性达到最高值;在大扁杏林农复合系统中,脲酶活性呈先升后降的变化特征。在各种林农复合系统中,蔗糖酶活性在6月较低,7-8月升高,9月开始逐渐降低。3种土壤酶活性间具有相关性,其中脲酶和蔗糖酶活性关系最为密切,相关系数在0．713以上。     

苦豆子多糖复合涂膜对成县樱桃贮藏品质的影响

以苦豆子半乳甘露聚糖为成膜基质,添加适量的CaCl2和柠檬酸为增塑剂,以甘油为成膜助剂,制备可食性复合膜,研究了常温(温度25℃～28℃,相对湿度68%～75%)下该复合涂膜保鲜剂对樱桃品质及生理生化指标的影响.结果表明:与对照组相比,该复合涂漠处理的樱桃其果实霉烂率、质量损失率及呼吸率明显降低,有机酸、VC等营养成分转化、流失的速度减慢;该复合涂漠可有效地抑制MDA、花青素的合成和相对电导率的升高,使PPO和POD酶活性处于较低的水平,延缓果实的衰老.     

紫叶李叶片花色苷超声辅助有机溶剂提取工艺

在单因素试验的基础上,运用Box-Behnken中心组合试验和响应面法考察了液料比、超声提取时间、温度3个因素对花色苷提取率的影响,并优化了提取工艺。结果表明,紫叶李叶片花色苷最佳工艺条件为：提取剂0.1%盐酸甲醇,超声（功率300W）提取时间5min,温度78℃,液料比51∶1（V/m）。在此条件下,花色苷的提取率预测值为2 291.96±72.37mg/kg,验证值为2 467.42±69.58mg/kg,与预测值的相对误差为7.42%,说明利用响应面法优化超声辅助有机溶剂提取紫叶李叶片花色苷工艺可行。     

Post-transplant growth of five deciduous ordic tree species as affected by transplanting date and root pruning

Shoot growth and leaf surface area were recorded during three seasons subsequent to transplanting five deciduous street tree species in Norway: Acer platanoides L., Aesculus hippocastanum L., Prunus avium L., Sorbus aucuparia L. and Tilia x europaea L. ‘Pallida’. Trees were transplanted at four dates, early and late autumn (August 25^th and October 23^rd), and early and late spring (April 23^rd and May 5^th–19^th, depending on species), with two root ball diameters (3 and 5 times the stem circumference). Control trees were not transplanted. Shoot growth in all species, except S. aucuparia, was reduced by 38 to 86% of control trees and leaf surface area by 13 to 61% in the first season after transplanting. In A. platanoides and A. hippocastanum shoot growth was also reduced in the second season (71 and 81% respectively). All species except A. hippocastanum resumed pre-transplant growth in the third season. Early autumn transplanting was least favourable in all the species, resulting in delayed establishment as well as reduced shoot growth and leaf surface area. Early spring transplanting was found favorable for A. platanoides and P. avium, but unfavorable for S. aucuparia. The experiment confirmed that the larger root balls are preferred over smaller root balls.     

Characterization and PCR-based detection of benzimidazole-resistant isolates of Monilinia laxa in California

Monilinia laxa is a pathogen of brown rot of stone fruit and almond in California, causing blossom blights and fruit rots. In this study, low-level resistance to the benzimidazole fungicides benomyl and thiophanate-methyl was detected in field isolates of M laxa collected from stone fruits and almonds in California. Low-resistant (LR) isolates grew in potato dextrose agar (PDA) plates amended with benomyl and thiophanate-methyl at 1 and 5 microg ml(-1), respectively, but not in plates amended with benomyl at 5 microg ml(-1) or thiophanate-methyl at 50 microg ml(-1). The benzimidazole LR isolates were characterized by temperature sensitivity and the DNA sequence of the beta-tubulin gene. The LR isolates showed high-temperature sensitivity, being sensitive to 1 microg ml(-1) of benomyl at 28 degrees C but resistant at 8-24 degrees C. Analysis of the DNA sequence of the beta-tubulin gene showed that the LR isolates had a point mutation at the amino-acid position 240, causing substitution of leucine by phenylalanine. Based on the point mutation, a pair of allele-specific PCR primers was developed for rapid detection of LR isolates of M laxa. In addition, a pair of PCR primers specific to M laxa was developed on the basis of the differences in the DNA sequence of the intron 6 of beta-tubulin gene from M laxa, M fructicola and other fungal species. The primer pair amplified the expected 376-bp DNA fragment from all M laxa isolates tested, but not from 14 other fungal species isolated from stone fruit and almond crops. The restriction endonuclease BsmA I recognized the sequence GTCTCC in the PCR products from sensitive (S) isolates only, but not the GTTTCC sequence in the PCR products from LR isolates. The endonuclease digested the 376-bp PCR products from S isolates to produce two bands (111 and 265 bp) on agarose gels. Thus, both allele-specific PCR and the PCR-restriction fragment length polymorphism (PCR-RFLP) methods could be useful for rapidly detecting benzimidazole-resistant isolates of M laxa from stone fruit and almond crops in California.     

On genetically remodeling the almond tree

Summary Dwarf peach trees require only 1/4th the space of standard trees and thus reduce the cost of experiments in which the tree is the experimental unit, by 75%. Or, put another way, they facilitate estimates of tree performance, in experiments of the same size, that are 50% more precise than those obtainable from standard trees. The objective of this study was to determine if the almond tree could be genetically compressed (dwarfed) to facilitate discrimination of genetic and cultural manipulation on its productivity, to facilitate genetic manipulation, and to increase its productive efficiency.The results obtained indicate the almond tree can be dwarfed (compressed), by the dw gene of peach. interspecific crosses of dwarf (dw/dw) peach, P. persica, with almond, P. amygdalus, followed by backcrosses to almond revealed: 1. Plant stature and node density vary widely among the dwarf (dw/dw) inter species hybrids. The heritabilities of these traits are high. 2. Spur density also varies widely. Its mean is high and its heritability is very high. 3. The dwarf inter species hybrids produce flowers copiously. However, at 22 months of age the flowers of most seedlings are sterile, apparently due to abnormal pistils. Consequently, average productivity is very low. However, some of these dwarf P. persica × P. amygdalus hybrids do express moderate to high productivity. Further, the heritability of productivity, among the seedlings expressing some degree of fertility, is very high. Consequently, further backcrosses to almond are expected to rapidly restore fertility and productivity. The yield potential of dw/dw dwarf almonds will remain unknown until fertility is restored.