甘肃河西走廊甜菜象虫种类分布及防治

据1986～1989年调查,甘肃河西走廊为害甜菜的象虫种类有:甜菜象、甜菜毛足象、甜菜碗额象等19种。其中以甜菜象、甜菜毛足象为优势种。药剂处理种子防治象虫试验结果表明:35％甲基硫环磷乳油、种子、水以2.2～3.0∶100∶100配方防治效果较佳,毒苗杀虫率达90.0％～92.0％,且残效期长,田间保苗率达83.5％～92.5％,挽回根产量损失29.7％～39.1％。     

Observations on the bulking and development of tuber size distribution in maincrop potatoes at Rothamsted in 1964–75

Summary Tuber samples taken at 2-week intervals from plots of cvs King Edward, Majestic and Pentland Crown in 1964–75 showed that the maximum bulking rates ranged from 1 to 5 tonnes/hectare/week. Maximum tuber numbers were usually produced by 11 weeks after planting and thereafter numbers declined. In September, about 70% of the tubers initiated were recovered, and between 24 and 52% of the tubers had reached marketable size (>4 cm). Tuber size distributions developed similarly in all years with all cultivars. During tuber initiation the distributions appeared as one population, and usually between 9 and 11 weeks after planting a second population of larger tubers developed. The population of small tubers later declined although in most years it was still present in September. This development fitted a model based on a mixture of two normal distributions and was determined by five parameters; the proportion of tubers in the small population and the means and standard errors of both populations.     

新疆8种十字花科植物的染色体数目

采用常规根尖压片法对十字花科8种植物的染色体数目进行了研究,试验结果表明,绒毛假蒜芥2n=14;无茎光籽芥2n=14;扭果花旗杆2n=14;厚壁荠2n=14;对枝菜2n=12;甘新念珠芥2n=14;爪花芥2n=4x=28;涩芥2n=4x=28.其中前6种为二倍体,后2种为四倍体;染色体基数除对枝菜n=6外,其余均为n=7,属较进化类型,8种染色体数目均为首次报道.     

论正切数(戴煦数)的计数意义

正切数(戴煦数)是1种与欧拉数相匹配的特殊函数和计数函数,作为独立的数学对象,19世纪中叶开始引起中外数学家的注意。本文着重分析了正切数在组合数学计数理论中的意义,简介西方数学家J.G regory(1671),Schlom ich(1857),Andre(1879,1881,1883,1894,1895),Estanave(1902),Schwartz(1931),Toscano(1936),Entrenger(1966)和Knuth,Buckholtz(1967)的成果。主要介绍晚清浙江数学家徐有壬(1840年前)、戴煦(1852)在中国数学史上的开创性工作和数学史界李俨(1955)等的研究。     

数论中一个著名公式的概率证法

在这篇论文中作者建立了一个概率模型。利用概率模型证明了数论中一个著名的公式。即(?)(1-1/(p~2))Ⅰ为素数集。     

荒漠草地地区伊犁绢蒿分枝数目对放牧强度的响应

试验于2012-2013年在新疆昌吉阿什里乡进行,以新疆荒漠草地典型植物种伊犁绢蒿(Seriphidium transiliense)为研究对象,研究了不放(CK)、轻度放牧(LG)、中度放牧(MG)和重度放牧(HG)下伊犁绢蒿各级分枝数、营养枝和生殖枝的变化规律,通过在生长季内多次采样方法(每30d采样一次),比较不同放牧梯度下各级分枝数数目,营养枝与生殖枝的数目,以揭示伊犁绢蒿构件数目对放牧强度的响应机制。结果表明,各放牧梯度下伊犁绢蒿各级分枝数在CK区表现为二级分枝数一级分枝数,在LG、MG和HG区则表现为分枝级数越高,分枝数越低;营养枝数目也在LG区表现有最大值,占全株分枝数的20.5%以上,营养枝数目的变化趋势为LGCKMGHG;生殖枝数在各放牧处理间与不放牧条件下大部分差异显著(P0.05),变化趋势为CKLGMGHG。     

Mating biology,nuclear DNA content and genetic diversity in spider plant (Cleome gynandra) germplasm from various African countries

Cleome gynandra (L.) Briq. is an African leafy vegetable with a potential to improve food security and micronutrient deficiencies. Cytological traits, breeding biology and genetic diversity of 30 selected entries of C. gynandra from six African countries were investigated. The entries consisted of advanced lines, gene bank accessions and farmers’ cultivars. Our study revealed chromosome numbers of 2n = 34 in root tip metaphase cells from one entry. The 30 entries were found to be diploid with genome sizes ranging from 2.31 to 2.45 pg/2C. Hand pollination experiments were carried out to assess self‐incompatibility within the entries and revealed that they are self‐ and cross‐compatible. For genetic diversity studies within and among the entries, the pooled data of 499 polymorphic bands from 11 amplified fragment length polymorphism primer combinations and nine simple sequence repeat markers were used. The genetic distance among the entries ranged from 0.13 to 0.77. In a principal coordinate analysis, the farmers’ cultivars formed a cluster separate from the advanced lines and the gene bank entries, and the latter were not well resolved.     

添加残次苹果发酵物对稻草青贮品质及其微生物数量的影响

为了探讨添加残次苹果发酵物改善稻草的青贮品质及其适宜添加比例。按残次苹果发酵物和稻草质量比为全部为稻草（Ⅰ）、1∶9（Ⅱ）、3∶7（Ⅲ）、5∶5（Ⅳ）、7∶3（Ⅴ）、9∶1（Ⅵ）混合进行青贮。青贮90 d 后开封，测定青贮前后的营养成分，鉴定青贮饲料的感官品质、发酵品质以及有氧暴露情况下pH值和微生物数量的变化。结果表明，添加残次苹果发酵物显著提高青贮原料的粗蛋白（Crude Protein，CP）和可溶性碳水化合物（Water Soluble Carbohydrate，WSC）的含量（P<0.05），降低了原料的中性洗涤纤维（Neutral Detergent Fiber，NDF）和酸性洗涤纤维（Acid Detergent Fiber，ADF）的含量（P<0.05）；青贮90 d天后，混合青贮饲料的乳酸（Lactate Acid，LA）、乙酸（Acetic Acid，AA）含量随着残次苹果发酵物添加量的增多而增加；处理Ⅰ的LA（0.17%）、AA（0.09%）含量最低，显著低于其他5个处理（P<0.05），而丁酸（Butyric Acid，BA）含量、AN/TN（Ammonia Nitrogen Total Nitrogen）的比值显著高于其他5个处理（P<0.05）；有氧暴露后，随着有氧暴露时间的延长，各处理的pH值、酵母菌数量、霉菌数量逐渐增多，乳酸菌数量逐渐减少；处理Ⅰ的乳酸菌数量始终显著低于其他各处理（P<0.05），酵母菌和霉菌数量始终显著高于其他各处理（P<0.05）；而处理Ⅲ、Ⅳ的乳酸菌数量始终显著高于其他处理（P<0.05），酵母菌和霉菌数量始终保持较低水平。未添加残次苹果发酵物处理Ⅰ的感官评分和综合评分均为劣等，添加残次苹果发酵物的稻草青贮处理Ⅲ和处理Ⅳ的感官评分和综合评分均为优等；同时添加残次苹果发酵物增加了混贮的营养价值，改善了混贮的发酵品质。综合分析，在试验中添加残次苹果发酵物能改善稻草的青贮品质，其添比例在3∶7～5∶5之间适宜。     

松梢象甲幼虫龄数及发育历期的研究

2005~2007年间,在黑龙江省朗乡林业局采用林间定期取样调查的方法,通过测量不同发育阶段幼虫的头宽,确定了松梢象甲幼虫的龄数;通过统计各龄幼虫数量和发育进度,用期距法确定了各龄幼虫发生盛期,并为当地松梢象甲的生产防治提出了最佳防治时间。     

高寒山区氮磷钾施肥技术对粳稻实粒数的影响

用五因素(1/2)二次正交旋转组合设计研究施氮量、基肥施氮比例、磷肥施用量、钾肥施用量及移栽密度对优良粳稻群体穗实粒数和单位面积内总实粒数的影响。结果表明:成熟期群体穗实粒数和单位面积内总实粒数之间对农艺措施的要求是一对矛盾;实现666.7 m2产量大于600 kg的主要农艺措施是:施氮量为:9.61~9.93kg/666.7 m2;基肥施氮比例为:47.38%~50.72%;磷肥施用量:4.05~4.39 kg/666.7 m2;钾肥施用量:6.49~6.94kg/666.7 m2;移栽密度:1.70~1.76万窝/666.7 m2。