同工酶与动物发生遗传学

本文对同工酶与动物发生遗传学各自的形成、发展以及二者的结合等问题作了概括的阐述。     

一次防治大豆灰斑病籽粒灰斑

通过室内及田间大豆不同生育期接种试验证明，籽粒感染灰斑病的关键时期是Ｒ３－Ｒ５期．Ｒ２期以前侵染不造成籽粒斑驳，据此提出一次防治大豆籽粒灰斑病的关键时期为Ｒ２－Ｒ４期．     

BPI基因在梅山猪初生断奶以及成年阶段的组织表达谱分析

为探讨杀菌/通透性增强蛋白(BPI)基因在梅山猪从初生到成年各个时期不同组织中的表达规律,利用qPCR检测初生、断奶、性成熟、体成熟4个重要发育时期(即1、35、134、158日龄)梅山猪的心脏、肝脏、脾脏、肺脏、肾脏、胃、肌肉、胸腺、淋巴结、十二指肠、空肠和回肠12个组织中BPI基因的表达水平。结果表明:4个不同发育阶段BPI基因的组织表达谱在心脏、肝脏、脾脏、肌肉和胸腺中均表现出相对一致的规律,即BPI基因的表达量一直处于极低水平,而在肠道组织中从初生到成年各时期均高度表达;BPI基因在胃中的表达程度随着日龄增长而显著提高;在小肠组织中,35日龄断奶仔猪BPI基因的表达水平极显著高于其他3个日龄。综上,推断肠道中BPI基因的高度表达是仔猪从初生就具有的抵抗大肠杆菌等病原感染属固有免疫的一部分,而在胃中的表达很可能是其后天为了抵御不断侵染的大肠杆菌等病原的结果。     

不同生长时期虎斑乌贼内壳营养成分含量分析比较

通过探究不同生长时期虎斑乌贼内壳的营养成分及矿物元素含量变化,为其开发利用提供理论依据。采用国家标准方法对不同生长时期(60、90、120、150日龄)虎斑乌贼内壳营养成分(水分、粗灰分、粗蛋白质、粗脂肪、多糖、氨基酸、脂肪酸)及矿物元素[5种常量元素——钠(Na)、钾(K)、镁(Mg)、铝(Al)、钙(Ca)和8种微量元素——铜(Cu)、铁(Fe)、锌(Zn)、硒(Se)、锰(Mn)、镉(Cd)、砷(As)、锶(Sr)]的含量进行测定。结果表明:不同生长时期时,粗灰分均是虎斑乌贼内壳的主要成分,含量为89.98%~92.06%,其含量随着生长不断增加,表现为150日龄时显著高于其他日龄时(P0.05);粗蛋白质的含量为2.82%~3.11%,其含量随着生长不断增加,表现为150日龄时显著高于60日龄时(P0.05);水分含量为3.93%~6.21%,其含量随着生长不断降低,表现为60日龄时显著高于其他日龄时(P0.05);相对于其他营养成分,虎斑乌贼内壳中粗脂肪、多糖含量较少,分别为0.41%~0.47%、0.34%~0.38%。不同生长时期的虎斑乌贼内壳中均检测出17种氨基酸,其中7种必需氨基酸(EAA)。不同生长时期的虎斑乌贼内壳中总氨基酸(TAA)、EAA和酸性氨基酸(AAA)含量分别为2.79%~2.93%、0.87%~0.98%和0.69%~0.87%,其中AAA含量随着生长不断增加,表现为150日龄时显著高于其他日龄时(P0.05)。各生长时期虎斑乌贼内壳中均以谷氨酸(Glu)含量(0.31%~0.43%)最高,组氨酸(His)含量(0.03%~0.07%)最低。不同生长时期的虎斑乌贼内壳中均检测出7种脂肪酸,包括3种饱和脂肪酸(SFA)、1种单不饱和脂肪酸(MUFA)和3种多不饱和脂肪酸(PUFA);在脂肪酸组分中以C22∶6n-3、C16∶0和C18∶0为主,其中C22∶6n-3含量(35.68%~37.62%)最高。生长时期对常量元素Na、Mg、Al和Ca及微量元素Cu、Zn和Sr含量有显著影响(P0.05),尤其是Ca、Mg、Zn含量,随着生长不断增加;重金属元素Cd、As含量很低,分别为0.001~0.003 mg/g和0.012~0.030 mg/g。综上所述,虎斑乌贼内壳营养丰富,Ca、M g、Zn含量高,且随着生长不断增加,具有良好的开发应用前景。     

两系稻在江西不同地区的生育特性及其育性转换初探

本研究通过不同地区的分期播种试验,观察了W6154S、5460S的生育特性和育性转换特性,指出了两个核雄性不育系的播种至始穗历期随纬度和海拔升高而增加,随栽培季节温度的升高而缩短。温度是诱导两个核雄性不育系育性转换的主导因素。同时提出了其制种与繁殖的适宜季节。     

Toxicity of azinphos-methyl to various development stages of the codling moth Cydia pomonella (Lepidoptera: Tortricidae)

The response to azinphos-methyl of different life-stages of the codling moth Cydia pomonella (L.) was studied. A similarity in response to azinphos-methyl (LC(50), LC(90)) was observed in neonate larvae obtained from the first and second generations of field populations. Mortality rates for neonate larvae of a field population cross-bred with a laboratory colony were lower (by a factor of 1.2-2.2) in comparison with field neonate larvae. The mortality rate of larvae from a laboratory colony exposed to artificial diet containing azinphos-methyl gradually decreased at older instars. The mortality rates of fifth-instar larvae were remarkably low when exposed to artificial diet mixed with azinphos-methyl or when topically treated with the insecticide. One- to three-day-old females were more sensitive than males of the same age, whereas the opposite was observed in 14-to 17-day-old adults. Mortality rates of 14- to 17-day-old adults were higher than those under 10 days old. No significant difference in sensitivity to the organophosphorus compound was noticed between the sexes of 7- to 10-day-old adults. Neonate larvae of the codling moth can serve as a target life-stage for various groups of pesticides, and the importance of using such a stage as a standardized methodology for monitoring resistance in the codling moth is discussed.     

14CO2 Assimilation and Translocation of 14C-Photosynthates by Different Parts of Indian Mustard (Brassica juncea L.)

The role of leaves, stem and reproductive parts in ¹⁴CO₂ fixation and subsequent photosynthate translocation was studied in Indian mustard ( Brassica juncea L.) at three growth stages. The data indicated that leaves, stem and pods are important sources of photosynthates for seed filling. At bud emergence stage leaves are the principle site of ¹⁴CO₂, fixation. The contribution of leaves declines at subsequent stages, where as the contribution of pod walls increased from bud emergence stage to ripening stage. The contribution of the stem remains more or less constant at all three growth stages studied. Although stem can fix ¹⁴CO², at bud emergence and flowering stages it imported ¹⁴C-photosynthates from leaves. However, stem exported photosynthates during subsequent growth stages.     

Agronomic Performance of Wheat (Triticum aestivum L.) as Influenced by Moisture Stress at Various Growth Stages and Seeding Rate

A field experiment was conducted at Samaru, Nigeria during the 1981–82 dry season to determine the yield and growth responses of wheat ( Triticum aestivum L.) to moisture stress imposed at various growth stages and to seeding rate. It was also to identify wheat growth stages that are most sensitive to soil moisture stress. Treatments tested include three seeding rates, namely, 75, 100 and 150 kg per ha, and seven drought treatments, effected by missing one or two consecutive irrigations at different growth stages.
Withholding irrigation at any growth stage prior to anthesis had detrimental effects on most of the growth characters and stress during crown root initiation (CRI) and jointing reduced most of the yield characters. Missing two consecutive irrigations at any given growth stage reduced grain yield more than did missing one irrigation; the greatest reductions in grain yield were 13 and 65% when one irrigation was missed at CRI and two consecutive irrigations were missed at jointing (the most sensitive growth stage) respectively. Moisture stress was also detrimental to number of grains, spike number, spike length, leaf area and number of tillers. A seeding rate of 100 kg per ha produced the best wheat performance in the present study.     

山西旱作节水农业发展战略的思考

根据山西省"十年九旱"的气候特征,结合2008年冬、2009年春特大干旱对生产的严重影响,提出了山西制定旱作节水农业发展战略的必要性和特殊意义,分析了战略缺位的深层次原因,并从水资源安全、粮食安全、生态安全、产业协调发展及科技创新等几个方面提出了思考建议和对策。     

Interaction between the effects of evaporation rate and amount of simulated rainfall on development of the free-living stages of Haemonchus contortus

A factorial experiment (3 x 4 x 2 x 3) was conducted in programmable incubators to investigate interaction between the effects of rainfall amount, rainfall distribution and evaporation rate on development of Haemonchus contortus to L3. Sheep faeces containing H. contortus eggs were incubated on sterilised soil under variable temperatures typical of summer in the Northern Tablelands of NSW, Australia. Simulated rainfall was applied in 1 of 3 amounts (12, 24 or 32 mm) and 4 distributions (a single event on the day after deposition, or the same total amount split in 2, 3 or 4 equal events over 2, 3 or 4 days, respectively). Samples were incubated at either a Low or High rate of evaporation (Low: 2.1-3.4 mm/day and High: 3.8-6.1 mm/day), and faeces and soil were destructively sampled at 4, 7 and 14 days post-deposition. Recovery of L3 from the soil (extra-pellet L3) increased over time (up to 0.52% at day 14) and with each increment of rainfall (12 mm: <0.01%; 24 mm: 0.10%; 32 mm: 0.45%) but was reduced under the High evaporation rate (0.01%) compared with the Low evaporation rate (0.31%). All rainfall amounts yielded significantly different recoveries of L3 under Low evaporation rates but there was no difference between the 12 and 24 mm treatments under the High evaporation rate. The distribution of simulated rainfall did not significantly affect recovery of infective larvae. Faecal moisture content was positively associated with L3 recovery, as was the ratio of cumulative precipitation and cumulative evaporation (P/E), particularly when measured in the first 4 days post-deposition. The results show that evaporation rate plays a significant role in regulating the influence of rainfall amount on the success of L3 transmission.