Effects of nitrogen and water stress on the rehydration,endogenous hormonal regulation and yield of maize

Water scarcity is known to be a strong limiting factor affecting maize grown and yield in cold semi-arid regions. Numerous studies have shown that rehydration improves maize growth. Our study aimed to explore the effects of rehydration treatments on maize growth and yield under water and nitrogen stress during different growth stages. We selected the drought-tolerant maize variety Nendan 19 (ND19) and subjected it to water stress during the V6 (sixth-leaf), R2 (filling) and R6 (maturity) growth stages and a rehydration treatment after each stress stage. Our results indicated that N1 (N100 kg N ha⁻¹) and N3 (N300 kg N ha⁻¹) treatments significantly increased the leaf moisture status relative to water content (RWC), bound water content (BWC), free water content (FWC) and water potential (WP)) at different growth stages. Similar trends were observed in the accumulation of plant leaf and root hormones (zeatin+zeatin riboside, indole-3-acetic acid, abscisic acid and gibberellic acid), photosynthetic pigments and chlorophyll fluorescence. However, under the same water stress conditions, they decreased as the N rate increased and reached a minimum value in the S3 (water stress for N3) treatments. In addition, with growth stage advancement and extension of the rehydration time, both showed a gradual upward trend. The results showed that to save water resources in the cold semi-arid region, rehydration treatments (R2S1 and R2S3) significantly increased the photosynthetic pigments and chlorophyll fluorescence parameters, leaf moisture status, biomass, 100-grain weight, hormone content, ear characteristics and grain yield of maize.     

Both TGF-β1 and Smad4 regulate type I collagen expression in the muscle of grass carp,Ctenopharyngodon idella

Fish Physiology and Biochemistry - Type I collagen is proven to make an important contribution to fish muscle quality. Our previous study has shown the Smad4-dependent regulation of type I collagen...     

西宁市林木植物检疫对象及防治

本文根据西宁市林木植物检疫对象普查结果,对其发生情况进行了综合分析提出相应的防治措施.     

福建省油茶林主要传粉昆虫种类及访花行为

对福建省福州、泉州、龙岩、南平、宁德等地油茶林传粉昆虫及其访花行为进行了调查,结果表明:福建省油茶林中主要传粉昆虫有24种,分属于3目11科17属,其中膜翅目的昆虫种类最多,有11种;大分舌蜂是油茶最重要的传粉昆虫,其数量多,传粉效率高;传粉昆虫日活动时间在12∶00—14∶30出现高峰,昆虫个体数量平均占全天总数的70%左右;油茶传粉昆虫的访花行为因昆虫的访花目的不同而有较大差异,温度和光照是影响传粉昆虫数量、行为和频率的主要因素。     

城市隧道事故车辆“快递”装置

近年来隧道作为城市道路的一种形式大量建设,并作为城市快速路或主干路的一部分。隧道内一旦发生事故,事故地点将成为交通瓶颈,通行能力急剧下降,若不及时清除事故车辆,易导致隧道及相邻路网的严重瘫痪。本文结合南京市玄武湖隧道,设计隧道内事故车辆的快速运输装置,旨在对事故车辆进行"快递",将事故的时间损失降到最低,尽快恢复隧道畅通。     

大豆浓缩蛋白在仔猪饲料中的应用

大豆浓缩蛋白(soybean protein concentrates,SPC)是以大豆为原料,经过粉碎、去皮、浸提、分离、洗涤、干燥等加工工艺,去除大豆中的油脂、低分子可溶性非蛋白组分(主要是可溶性糖、灰分、醇溶蛋白和各种气味物质等)后所得到的大豆深加工产品。蛋白质含量高,食品级SPC一般不低于70%(干物质基础),故又称70%蛋白粉。由于消除了寡聚糖类胀气因子、胰蛋白酶抑制因子、凝集素和皂甙等抗营养因子,营养素消化率有一定程度的提高,而且改善了产品风味和品质。从NRC(1998)的数据来看,其氨基酸的表观消化率甚至普遍高于脱脂奶粉和血浆蛋白粉(见表1)…     

番茄品种耐弱光性的综合评价

研究了苗期弱光条件对幼苗素质，开花，果实大小及产量的影响，采用模糊数学的隶属法对品种的耐弱光性进行评价，并探讨了番茄耐弱光性状的鉴定方法，结果表明，苗期弱光对幼苗素质影响最大，其次影响开花，果实大小和产量，春雷２号和春雷１号属于耐弱光惭弱的品种，白果强丰属不耐弱光品种。     

四种限制性内切酶对美国白蛾核型多角体病毒DNA酶解分析

从HcNPV中直接分离提纯的DNA证明具有典型的紫外吸收光谱。经琼脂糖电泳后是一条带谱。用限制性内切酶EcoRⅠ、PstⅠ、BglⅡ、PVUⅡ酶解,经琼脂糖平板电泳分别产生19、22、18、22条核酸片段。以λDNA-EcoRⅠ和λDNA-HindⅢ片段作参考,计算出各片段分子量大小,积加得平均值为94.0445×10~8。     

浅议林业企业负债经营

负债经营可给企业带来利益 ,但如使用不当会给企业带来不利影响 ,导致企业破产 ,当资产利润率大于负债利息率时 ,负债经营可使自有资金利润率扩大 ,但同时财务风险提高。林业企业在经营活动中应适度把握负债比例 ,并考虑 8个方面的问题 ,善于经营负债。     

果蔬汁加工技术进展

我国是水果和蔬菜生产大国,产量均居世界第一位。发展果蔬汁产业可以提高果蔬的附加值,具有明显的经济和社会效益。近年来,我国果蔬汁的加工技术取得了一定的进步。介绍了近年果蔬汁饮料加工领域的新技术,以及果蔬加工的发展方向。