辽西地区春播期土壤湿度变化特征及气象影响因子分析

利用1981—2011年辽西地区土壤相对湿度、降水和气温资料,对该区土壤湿度和降水变化特征及二者关系进行分析。结果表明：土壤湿度具有明显干化趋势,同期降水不是唯一影响因子;春播期土壤湿度与前秋降水正相关,深层相关系数为0.69,与底墒显著正相关,相关系数最高可达0.84,如此显著的正相关是由于北方特有的封冻雨,秋季降水封冻在土壤里,到第二年春季,气温升高,解冻返浆,土壤变得湿润;5月土壤湿度与同期降水呈正相关,浅 层相关系数为0.67,与气温呈负相关,深层相关系数为-0.58。     

Density effects on length at maturity of walleye pollock <Emphasis Type="Italic">Theragra chalcogramma</Emphasis> off the pacific coast of northern Japan in the 1990s

To determine how stock abundance fluctuations of walleye pollock Theragra chalcogramma are related to variations in reproductive characteristics, the length at 50% maturity of the fish sampled off the Pacific coast of northern Japan from 1990 to 1999 was examined. In both sexes, the fish density increased, and the body length of age-3-5 fish decreased, but the condition factor and the age at 50% maturity showed no clear trend during this period. Male length at 50% maturity decreased, while value for females showed no clear trend. In both sexes, significant negative correlations were found between density index (combined age-3-5) and each body length at age-3-5. Significant positive correlations were seen between each body length at age-3-5 and length at 50% maturity in males. Positive correlation between body length at age-5 and length at 50% maturity was significant in females from 1990 to 1999, except for the samples in 1998. We suggest that the fish density might affect the length at maturity in males and possibly also in females.     

干旱胁迫下2种香蕉幼苗叶片和根的主要渗透调节物质的变化

本文研究了不同干旱胁迫下抗旱性不同的帝王蕉和粉蕉幼苗叶片和根系的可溶性蛋白质和可溶性糖主要渗透调节物质的含量变化。结果表明：2种香蕉幼苗叶片可溶性蛋白质和可溶性糖含量随着干旱胁迫程度的增加而显著增多;根系可溶性蛋白质和可溶性糖含量并未持续上升,而是重度胁迫低于中度胁迫,但仍高于对照和轻度胁迫。干旱胁迫后,除帝王蕉根系可溶性糖含量外,帝王蕉根系可溶性蛋白质、粉蕉根系可溶性蛋白质和可溶性糖含量在3个胁迫程度下增加幅度均大于叶片增加幅度,且粉蕉较帝王蕉更能适应干旱胁迫环境。本文将为香蕉抗旱品种选育和栽培提供一定的理论依据和实践意义。     

干旱胁迫下新源1号新疆野苹果抑制性差减文库的构建与初步分析

为分离和鉴定新疆野苹果(Malus sieversii Roem.)根组织干旱胁迫条件下差异表达的基因,以苗龄为3个月的新源1号新疆野苹果水培苗为材料,应用20%PEG 6000溶液处理模拟干旱胁迫,利用抑制性差减杂交(SSH)的方法构建了新疆野苹果根组织干旱胁迫诱导表达差减文库(正库)和抑制表达差减文库(反库).正库和反库随机各挑菌500个,菌落PCR显示插入片段在250~1000 bp之间.测序鉴定后共得到268个有效UniESTs.经Blastx和Blastn等生物信息学方法分析表明全部的UniESTs按可能的生物学功能可被分为16个大类,包括新陈代谢、能量、转录、蛋白质合成、蛋白质修饰降解、DNA加工、细胞信号转导等.     

聚乙二醇（PEG6000）模拟干旱胁迫抑制矮沙冬青种子的萌发

本研究以新疆特有濒危保护植物矮沙冬青（Ammmopiptanthus nanus（M．Pop．）Chengf）的种子为材料,用不同渗透势浓度的聚乙二醇（PEG6000）模拟干旱胁迫,探讨干旱胁迫对矮沙冬青种子发芽率、平均发芽速度、胚轴和胚根长度及发芽指数、活力指数的影响。结果表明,不同浓度PEG胁迫处理均降低了种子的发芽率,延缓了矮沙冬青种了萌发进程;种子的发芽率、发芽指数和活力指数均随胁迫强度的增加呈明显下降趋势。当-1．20MPa的PEG胁迫处理的种子在试验结束时仍未能萌发,表明-1．20MPa是矮沙冬青种子萌发的临界水势。PEG模拟十旱胁迫中,当PEG处理为-0．2MPa时,虽然最终发芽率与对照一样,但其胚根、胚轴的长度都比对照短,说明矮沙冬青胚根、胚轴的生长比发芽率对干旱胁迫更敏感。干旱胁迫可能是导致矮沙冬青种群天然更新能力弱的原因之一。本研究将为矮沙冬青种质资源的保护和种群的恢复提供科学依据。     

Identification of sources of resistance to damping-off and early root/hypocotyl damage from Rhizoctonia solani in common bean (Phaseolus vulgaris L.)

Rhizoctonia solani causes economically important root and hypocotyl diseases in common bean throughout the world. Root health is a vital factor in plant development and root diseases would negatively influence water and nutrient uptake as well as cause direct stand reduction and root rot damage to the crop. An efficient common bean screening method to evaluate damping-off and early root/hypocotyl damage from R. solani was developed and used to identify dry bean lines with levels of resistance to this disease. Two sets of 163 and 111 lines previously evaluated for drought tolerance in Nebraska and Puerto Rico were evaluated for damping-off resistance and early root/hypocotyl damage under greenhouse conditions. Disease severity on plants was identified based on above-ground symptoms, seedling survival and root lesions using a rating scale of 1 (resistant) to 9 (susceptible). In the first set of lines representing commonly grown dry bean cultivars, germplasm and sources of damping-off resistance, the Rhizoctonia mean rating ranged from 1.7 to 3.9; Phaseolus vulgaris lines PI 310668 and PI 533249 had the highest damping-off resistance. In the second set of the best lines from a drought tolerance shuttle breeding program the Rhizoctonia mean rating was between 2.6 and 5.7. The availability of drought tolerant dry bean lines allowed the testing of the hypothesis that there was a correlation between selecting for drought tolerance and R. solani damping-off resistance. No correlation between mean disease rating and drought tolerance was found, but adapted dry bean lines such as NE14-08-176 released as SB-DT1, and NE14-08-225 were identified with moderate damping-off resistance and drought tolerance. Lines with both traits and other attributes will facilitate development of resistant bean cultivars to manage damping-off caused by R. solani.     

干旱条件下花生品种筛选试验

以山东省12个主推大花生品种为试材，研究干旱条件（播种至开花下针期不浇水）下各品种的表现，筛选出4个适宜菏泽生态条件栽培的抗旱品种，其主茎高平均36．1cm，侧枝长平均39．6cm，主要农艺性状间表现出正相关性；不抗旱品种营养相关性状与产量相关性状表现为负相关。     

Drought Resistance Improvement in Rice: An Integrated Genetic and Resource Management Strategy

Abstract

Drought is the major constraint to rice production in rainfed areas across Asia and sub-Saharan Africa. In the context of current and predicted water scarcity, increasing irrigation is generally not a viable option for alleviating drought problems in rainfed rice-growing systems. It is therefore critical that genetic management strategies for drought focus on maximum extraction of available soil moisture and its efficient use in crop establishment and growth to maximize biomass and yield. Extensive genetic variation for drought resistance exists in rice germplasm. However, the current challenge is to decipher the complexities of drought resistance in rice and exploit all available genetic resources to produce rice varieties combining drought adaptation with high yield potential, quality, and resistance to biotic stresses. The strategy described here aims at developing a pipeline for elite breeding lines and hybrids that can be integrated with efficient management practices and delivered to rice farmers. This involves the development of high-throughput, high-precision phenotyping systems to allow genes for yield components under stress to be efficiently mapped and their effects assessed on a range of drought-related traits, and then moving the most promising genes into widely grown rice mega-varieties, while scaling up gene detection and delivery for use in marker-aided breeding.     

干旱胁迫对豫楸1号嫁接苗的生理生化影响研究

以1年生豫楸1号四种砧木嫁接苗(金丝楸、豫楸1号、灰楸和梓树)为试验材料通过盆栽干旱胁迫以正常浇水处理为对照,研究了不同程度干旱胁迫对这四种不同砧木豫楸1号嫁接苗在保护酶活性、脂膜透性、过氧化物的反应物积累和细胞渗透调节性物质等方面的生理生化影响。结果表明:保护酶SOD活性先上升后下降,活性表现明显的是金丝楸嫁接苗;MDA的积累都有明显增加,金丝楸嫁接苗积累最少,增加较多的是梓树嫁接苗和灰楸嫁接苗;脂膜透性都有不同程度的上升,其中梓树嫁接苗和灰楸嫁接苗上升较快,金丝楸嫁接苗积累较少。可溶性蛋白的含量都有不同程度的上升,其中金丝楸嫁接苗积累较多。经过对几项生理指标的综合方差[1]分析,认为金丝楸嫁接苗相对于其他三个品种具有较强的抗旱能力。     

水曲柳厚板材的干燥工艺

采用高温干燥与常规干燥相结合的工艺技术，干燥水曲柳厚板材，经多次实践证明，不仅缩短干燥周期，而且提高了干燥质量。