发动机配气机构弹簧有限元分析

气门弹簧是发动机配气机构的重要组件之一,气门弹簧是否符合技术要求是发动机能否正常工作的关键。对弹簧进行强度、刚度、抗疲劳强度以及模态分析,分别采用耦合式有限元分析法和夹板式有限元分析法对弹簧进行了对比分析,发现弹簧内侧为弹簧的易疲劳区,弹簧的强度、刚度、抗疲劳强度满足技术要求,没有共振现象。研究还表明,夹板式有限元分析法比耦合式准确。     

Australian Uromyces viciae-fabae: Host and nonhost interaction among cultivated grain legumes

Uromyces viciae-fabae, rust of faba bean, parasitizes other legume crops such as lentils (Lens culinaris) and field peas (Pisum sativum) in some environments. In this study we examined the host range of two Australian isolates of U. viciae-fabae collected and purified from a faba bean crop and classified as U. viciae-fabae ex V. faba. Field pea (P. sativum), chickpea (Cicer arientinum), lupin (Lupinus spp.), lentil (L. culinaris), and mung bean (Vigna radiata) genotypes were tested with these isolates, as well as resistant and susceptible genotypes of the faba bean host. Race specificity for these two pathogen isolates was observed on Vicia faba, with two faba bean genotypes showing partial resistance. Both U. viciae-fabae isolates also colonized field pea seedlings and successfully produced uredinia under glasshouse conditions, despite this fungus not being known as a pathogen of Australian field pea crops. No sporulation of either isolate of U. viciae-fabae ex V. faba was observed on any of the remaining legume species tested. However, obvious differences in fungal growth were observed, ranging from small infection sites with very rare haustorium formation in mung bean to more extensive growth and the development of potential uredinial structures in chickpea. These observations are discussed in relation to the phylogenetic relationship of these host and nonhost species.     

云南小麦品种（系）锈病和赤霉病抗性功能基因的KASP标记检测

利用5个锈病成株期抗性基因的KASP标记Sr2_ger9 3p、Lr34jagger、CSTM4_67G、Lr68-2、VPM_SNP和抗赤霉病基因Fhb1的KASP标记TaHRC-KASP,对云南省育成的42个小麦品种（系）进行检测,旨在筛选出含有目标基因的优异小麦种质,为云南省持久抗病小麦新品种（系）的选育提供材料。结果表明,4个材料含兼抗型成株抗锈病基因Lr34/Yr18/Sr57,频率为9.52%;6个品种（系）含兼抗型成株抗锈病基因Lr67/Yr46/Sr55,频率为14.29%;7个材料含抗慢叶锈病基因Lr68,频率为16.67%;含兼抗型成株抗锈病基因Sr2/Yr30和成株抗叶锈基因Lr37的材料各有1个,频率均为2.38%;未检测出含抗赤霉病基因Fhb1的品种（系）。云麦69、云麦75、云麦56、宜麦1号和宜麦3号等兼有2个成株期抗锈病基因,可作为今后云南持久抗锈病育种的抗源材料。     

我国云南、湖北和山东葡萄产区霜霉病菌对甲霜灵的抗性检测

为明确我国云南省宾川县、湖北省公安县和山东省烟台市葡萄产区霜霉病菌对甲霜灵的抗性发生态势,采用叶盘漂浮法测定了这3个产区共127株葡萄霜霉病菌对甲霜灵的抗性频率及抗性水平。结果显示,不同区域间病菌的抗性频率和抗性水平均存在差异。其中,湖北省公安县霜霉病菌的抗性频率和抗性水平均较高,抗性频率达92.0%,高抗菌株占76.0%,低抗菌株占16.0%,敏感菌株占8.0%;山东省烟台市霜霉病菌的抗性频率为74.0%,低抗菌株占64.0%,高抗菌株占10.0%,敏感菌株占26.0%;云南省宾川县霜霉病菌的抗性频率和抗性水平均较低,抗性频率为29.6%,敏感菌株占70.4%,低抗菌株占29.6%,无高抗菌株。     

水分胁迫对不同抗旱型玉米自交系苗期生长的影响

通过水分胁迫处理对不同抗旱型玉米自交系苗期的影响研究,为抗旱育种选择自交系提供选择参考。采用人工控水的方法,研究干旱胁迫对夏玉米抗旱型和对敏感型自交系苗期株高、地上部和地下部分干重、叶面积、比叶重、叶绿素和净光合速等的影响。结果表明：不同抗旱型自交系苗期对水分胁迫的响应不同。抗旱玉米自交系从5叶期开始在干旱胁迫期间的株高、地上部和地下部分干重、叶面积、叶绿素和净光合速率等指标均高于对水分敏感的玉米自交系,且比叶重相对稳定。这表明干旱条件下,抗旱型自交系较普通自交系在苗期能够表现出更好的适应性,本研究对加强抗旱自交系的筛选和选育,进一步提高耐旱节水玉米新品种选择效率具有一定参考价值。     

接骨木无性系苗期干旱胁迫响应及抗旱性综合评价

为揭示不同种接骨木无性系的抗旱性,探讨其对干旱环境的适应能力,为干旱瘠薄山地造林提供材料。采用盆栽法进行自然干旱胁迫试验,运用主成分分析对不同处理下各无性系生理指标进行综合评价。结果表明：干旱胁迫下,无性系PT-1的生物量增量最大,PT-2的根冠比最大。在干旱胁迫逐增情况下,细胞膜透性逐增,当干旱达到中、重度时,无性系PT-1和PT-2的细胞膜透性最小。叶绿素含量及超氧化物岐化酶活性均随干旱程度增加呈先增后降趋势。随干旱胁迫增加可溶性糖和脯氨酸均随之增大。在重度干旱胁迫下,无性系PT-1的可溶性糖含量最大。主成分分析得出,各无性系抗旱能力由强到弱为：XY-2、JY-1、XY-1、XY-3、PT-1、PT-3、PT-2。其中,XY-2、JY-1具有较强抗旱性,可初步作为抗旱材料进行后续研究。     

甘蔗与蔗茅杂交亲本及后代材料的抗旱性鉴定

研究旨在筛选出优良抗旱育种材料,为今后甘蔗抗旱育种和抗旱栽培技术提供重要的理论依据。采用盆栽干旱处理,测定蔗茅野生种无性系、甘蔗栽培品种（系）及其杂交后代共12份材料苗期与抗旱相关的8项生理生化指标,利用极点排序法对供试材料的抗旱性进行了综合评价。结果表明：干旱胁迫下,12份供试材料的Pro、MDA、SS及PMP均呈上升趋势,SP、Chl和SOD活性呈下降趋势,CAT活性有升有降。极点排序法分析表明,12个供试材料的抗旱强弱为：‘蔗茅99-2’>‘蔗茅99-1’>‘蔗茅99-4’>‘蔗茅I91-8’>‘蔗茅99-3’>‘蔗茅90-29’>‘滇蔗01-58’>‘滇蔗04-14’>‘滇蔗02-39’>‘蔗茅II91-2’>‘新台糖10’>‘崖城89-9’,说明蔗茅优质抗旱性状可以通过基因渗透方式传递给后代。在苗期干旱胁迫下,‘蔗茅99-2’在渗透调节等方面表现出积极的生理响应。     

How does water and salt stress affect the germination and initial growth of Brazilian soya bean cultivars?

The effects of water and salt stress on rate of germination and seedling growth were investigated under laboratory conditions in 46 soya bean genotypes from Central-West region of Brazil to verify how these stresses may limit crop establishment during the initial growth stage and also to identify the most tolerant genotypes to drought and salinity. Mild water and salt stresses were imposed by seed exposure to –0.20 MPa iso-osmotic solutions with polyethylene glycol—PEG 6000 (119.57 g/L) or NaCl (2.357 g/L) for 12 days at 25°C. The germination percentage, seedling length and seedling dry matter were measured, and then, salt or drought tolerance indexes were calculated. The “NS 5909 RG,” “NS 7000 IPRO,” “NS 7338IPRO,” “FPS Solimões RR,” “NS 5151 IPRO,” “SYN 13610 IPRO,” “LG 60177 IPRO,” “NS 6909 IPRO” and “BMX Desafio RR” were identified as the most drought-tolerant genotypes, whereas under salinity conditions, the genotypes “5D 615 RR,” “BMX Desafio RR,” “5D 6215 IPRO” and “BMX Ponta IPRO” were identified as tolerant. The “BMX Desafio RR” is the genotype most adapted to both stress conditions and, therefore, should be used under conditions of water shortage and excess salt in the soil at sowing time.     

水杨酸诱导对苹果体内防御酶活性的影响

为研究叶面喷施水杨酸(SA)对不同苹果品种防御酶活性的影响,以抗病品种‘北之幸’和感病品种‘礼泉短富’为试验材料,对不同浓度水杨酸处理前后的苹果叶片进行防御酶活性测定。结果表明,经水杨酸处理后,‘北之幸’和‘礼泉短富’的β-1,3-葡聚糖酶、POD、PAL和PPO活性均有提高,且高于对照植株。其中‘北之幸’的β-1,3-葡聚糖酶、POD、PAL和PPO活性分别是对照的2.04倍,6.19倍,2.73倍和2.32倍;‘礼泉短富’的β-1,3-葡聚糖酶和PAL活性分别是对照的1.82倍和1.70倍,POD活性是对照的5.68倍,PPO活性是对照的4.00倍。由此可见,水杨酸处理可以不同程度的提高植株体内抗性相关酶的活性,但不同品种间存在差异。     

外源调节物质对盐胁迫下植物生长调控研究进展

为了探究外源物质对植物耐盐性的调控机理及进一步利用外源调节物质提高作物耐盐性,归纳了五大类传统植物激素（生长素、赤霉素、乙烯、脱落酸、细胞分裂素）以及褪黑素、水杨酸、多胺、油菜素类固醇、茉莉酸类等外源生长调节物质对盐胁迫下植物生长的调控情况。同时总结了硅、钙等离子类外源调节物对盐胁迫下植物生长的调节作用,多种外源调节物质可通过增强光合作用、提高渗透势、增加抗氧化酶活性及减少离子毒害等方式来减轻盐害。本文为进一步利用单一或复合外源调节物质来缓解作物盐害盐提供理论依据。