早稻纹枯病预测和管理模型——RSPM－1的应用研究

简要介绍了ＲＳＰＭ－１系统的特点，并对各部分的演算进行了改进和简化，使该系统能在函数型计算器上得以实现     

水稻纹枯病预测和管理模型——RSPM-1

 RSPM-1是一个用于连作早稻纹枯病预测和药剂控病管理的系统动态模型。该模型由早稻生长、病情进展预测、作物受害损失估计和用药管理决策四个子模型组成。组装成的程序系统，以早稻栽插期、氮肥用量、气象条件、起始病情等为驱动变量，在微机上运转后，打印出各期病情、稻谷减收率、应采取的防治决策和所得纯收益。     

Silicon: a beneficial nutrient for maize crop to enhance photochemical efficiency of photosystem II under salt stress

Soil salinity imposes an unprecedented risk to the soil fertility and availability of plant nutrients. The present proposal is designed to address the effect of salt stress on photosynthetic apparatus of maize including chlorophyll a fluorescence and how silicon nutrition helps to overcome this issue. In a sand culture experiment, two maize cultivars were sown in small pots with two levels of silicon (0 and 2 mM H₂SiO₃) and two levels of salinity stress (0 and 60 mM NaCl). Salinity stress reduced dry matter yield and potassium (K) concentration in both maize cultivars and also induced inefficient working of photosynthetic apparatus including photochemical efficiency of photosystem II. Silicon addition alleviated NaCl stress on maize crop by improving the dry matter yield and water use efficiency (WUE). It decreased shoot Na concentration by increasing root and shoot K concentration of maize plants. It enhanced maximum quantum yield of primary photochemistry which leads to smooth electron transport chain. It also significantly enhanced shoot silicon concentration and has a significant positive correlation with WUE. Therefore, silicon-treated maize plants have better chance to survive under salt stress conditions as their photosynthetic apparatus is working far better than non-silicon-treated plants.     

Chemical and antioxidant properties of Laurocerasus officinalis Roem. (cherry laurel) fruit grown in the Black Sea region

Laurocerasus officinalis Roem. is a summer fruit highly characteristic of the Black Sea region. The edible parts of the fruit were tested for chemical composition and antioxidant properties. Total moisture, ash, protein, sugar, pectin, ascorbic acid, phenolic, and mineral contents of the fruit were determined. The antioxidant activity of the fruit was investigated using TLC plate and ferric thiocyanate methods. Its antioxidative character was also tested utilizing hydroxyl, DPPH, and superoxide radical scavenging activity measurements, using BHT, vitamin C, and Trolox as references. Besides being a good source of nutrients, L. officinalis was found to provide a rich source of protective antioxidant compounds. Its antioxidant and radical scavenging activities were comparable to or higher than those of the reference antioxidants. It appeared to have high mineral content. The concentrations of macroelements K, Mg, Ca, and Na were high at 2215 +/- 10.5, 179 +/- 11, 153 +/- 0.8, and 55 +/- 0.3 mg/kg, respectively, and the concentrations of trace elements Mn, Fe, Zn, and Cu were 24.2 +/- 1.3, 8.3 +/- 0.8, 1.9 +/- 0.2, and 0.8 +/- 0.1 mg/kg, respectively. In addition, the fruit showed very low contents of Pb, Ni, Co, and Cr, below the detection limits, which is considered to be a good food quality. As it is a rich source of protein, sugar, ascorbic acid, minerals, and antioxidants, L. officinalis is well worth further studies regarding its components possessing important health benefits and inclusion in the daily diet.     

Feeding balanced ration can improve the productivity and economics of milk production in dairy cattle: a comprehensive field study

Tropical Animal Health and Production -     

Adult rabbits acquire resistance to lethal calicivirus infection by adoptive transfer of sera from infected young rabbits

Calicivirus infection of adult rabbits induces the so-called rabbit haemorrhagic disease (RHD) that kills 90% or more of the infected animals; in contrast, young rabbits (up to 8-week-old animals) are resistant to the same infectious agent. We report that calicivirus inoculation of young rabbits induced moderate titres of antiviral antibodies. When these rabbits reached adulthood, a second calicivirus inoculation resulted in resistance to RHD and boosting of antibody titres in half of the rabbits. Adoptive transfer of sera from calicivirus-infected young rabbits to na?ve adult rabbits conferred resistance to RHD. We conclude that calicivirus infection of young rabbits induces specific anti-calicivirus antibodies that will protect them from RHD when they reach adulthood.     

Effect of various levels of dissolved oxygen on reactive oxygen species and cryocapacitation‐like changes in bull sperm

The present investigation was carried out to study the effect of various levels of dissolved oxygen (DO) on reactive oxygen species (ROS) and cryocapacitation‐like changes in bull sperm. Egg yolk–Tris–glycerol (EYTG) extender was split into four subextenders; viz., Extender I (control; no flushing with liquid nitrogen (LN₂)), Extender II, Extender III and Extender IV were flushed with LN₂ for 40, 16 and 8 min, respectively. The DO levels were standardized to 11.7, 2, 4 and 8 ppm, respectively, in control (Extender I), Extender II, Extender III and Extender IV. Ejaculates with mass motility of ≥ 3+ were divided into group I (diluted with Extender I), group II (diluted with Extender II), group III (diluted with Extender III) and group IV (diluted with Extender IV) up to 80 × 10⁶ sperm/ml. Extended semen samples were packed in French mini straws (0.25 ml), equilibrated and cryopreserved. Semen samples were evaluated at prefreeze and post‐thaw stage for various parameters (DO, progressive motility (PM), viability (VIB), acrosomal integrity (AI), hypo‐osmotic swelling (HOS) test, ROS, cholesterol (C) and phospholipid (P). The percentage of PM, VIB, AI, HOS test, cholesterol (C) and phospholipid (P) levels, and capacitated sperm were significantly (p < 0.05) higher in groups III and IV as compared to groups I and II. However, the acrosome‐reacted sperm (%; pattern AR) were significantly (p < 0.05) decreased in group III as compared to all other groups. Besides the proportion of sperm displaying tyrosine‐phosphorylated pattern, EA (fluorescence at both equatorial and anterior acrosomal regions, i.e. high capacitation level) was significantly (p < 0.05) reduced in group III compared to all other groups. In conclusion, varying DO levels in the extender significantly affect sperm quality, ROS production and capacitation‐like changes in bulls.     

宁夏盐池南海子湿地交错带判定及植被稳定性分析

为研究半干旱区盐碱湿地生态交错带及其植被群落多样性和稳定性,于2016年7月通过样方(1m×1m)调查法对哈巴湖自然保护区的南海子湿地进行了野外植被调查。首先通过游动分割窗技术将研究区定量划分为湿生带、交错带和旱生带3个不同生活环境地带(以下简称生境带),采用Shannon-Wiener指数、Simpson指数、Pielou均匀度指数、Margalef物种丰富度指数分析不同样线不同生境带间的植物群落多样性,采用M.Godron稳定性测定方法分析不同生境带植物群落稳定性。结果表明,1)东、西样线窗口宽度为6个样方,南、北样线窗口宽度为8个样方时交错带的边界可以被清晰地划定;2)不同样线不同生境带Shannon-Wiener多样性指数、Pielou均匀度指数和Simpson优势度指数的排列顺序均为交错带旱生带湿生带,而Margalef物种丰富度指数的排列顺序为湿生带旱生带交错带;3)湿生带植物种数最少,以耐盐碱植物为主,植被群落最稳定,旱生带次之,交错带植被种数最多,群落最不稳定。     

大丰麋鹿群对光周期适应的研究*

１９８７－１９９２年研究表明，江苏大丰麋鹿保护区半野生放养的麋鹿，产仔季节比在英国伦敦时提前２５ｄ，雄鹿落角季节比引进初期提前２２ｄ，发情期亦有相应变化。其节律的季节分布情况与１９世纪９０年代生活在伦敦乌帮夺的情况有着惊人的一致，表明鹿群已重新适应了大丰的光周期，它的生命季节性节律已调整在位；逐年产仔期变动显示了调整的具体过程。