低山丘陵区牧草引种和提高山地生物生产力的研究

通过在太行山低山丘陵区的试验研究，系统地总结了在干旱山地人工种草从引种栽培的一系列综合配套技术，从一个侧面反庆子干旱山地综合治理中，牧草与林果的复合栽培在培肥土壤，改良低产农田和提高果园生产力等方面的作用；为在太行山区开展人工种草提供了依据。     

牧草抗旱机理与节水灌溉技术研究

在干旱、半干旱地区，牧草因长期处于亏水环境中，形成了一定的抗性，存在一个较宽的对水分利用相对较高的生理耗水阈值。木文从这一水分生理角度出发，在充分研究牧草生理生态适旱系列变化过程的基础上，确定了几种干旱半干旱草地的经济耗水量，并制定出相应的经济灌溉制度。     

牧草中的水溶性碳水化合物

牧草中有适量的水溶性碳水化合物对家畜及牧草都有十分重要的意义。本文从牧草中水溶性碳水化合物的种类、影响因素、贮存过程中的损失和对家畜的营养价值等方面加以综述。     

Regulation of root-to-leaf Na and Cl transport and its association with photosynthetic activity in salt-tolerant soybean genotypes

ABSTRACT

Soil salinity is a major constraint to sustainable crop production. Genetic improvements are needed for growing soybean in salinity-prone environments. Salt-tolerant soybean genotypes alleviate a reduction in photosynthesis and growth under saline conditions; however, the detailed mechanisms involved remain unclear. Here, we aimed to clarify how Na and Cl root-to-leaf transport is quantitatively regulated, and to identify whether photosynthetic tolerance depends on traits associated with either stomata or with mesophyll tissues. Two pairs of pot-grown soybean near-isogenic lines (NILs) consisting of tolerant and susceptible counterparts, derived from a cross between salt-tolerant FT-Abyara and salt-sensitive C01, were subjected to salinity treatment in a rainout greenhouse. Comparison of photosynthetic responses between genotypes indicated that genotypic differences in salinity tolerance depended on the ability for sustained CO₂ assimilation in mesophyll tissues, rather than stomatal conductance. The ratio of photosynthetic rate to intercellular CO₂ concentration (A/Ci) declined exponentially with increasing Na and Cl concentration regardless of genotype, but tolerant genotypes effectively kept both elements at significantly low levels. Under saline conditions, tolerant genotypes reduced Na and Cl content at the two transport pathways: from root to stem, and from stem to leaf, but the reduction of Cl at each pathway was only minor. These results suggest that integrating genetic capacity for Cl transport regulation and osmotic adjustment should be an important target in salinity-tolerance soybean breeding.     

Significance of salt transport patterns in rice varieties differing in salt tolerance

Abstract

The absorption mechanisms for Na, K, SO₄ and Cl were tested in a salt tolerant (PVR 1) and a salt sensitive (GEB 24) rice varieties. The salt tolerant variety accumulated significantly larger amounts of Na than the salt sensitive variety. Further, PVR 1 absorbed SO₄ from Na₂SO₄ in preference to that from K₂SO₄. The absorption patterns for K and Cl were similar in both the varieties. It is concluded that the capacity of plant species to accumulate greater amounts of Na is a reflection of their halophytic feature.     

D型魏氏梭菌毒素研究进展

魏氏梭菌病是由魏氏梭菌引起的一种重要的人兽共患传染病。可导致各种动物的肠毒血症或坏死性肠炎,D型魏氏梭菌病包括牛、羔羊、绵羊、山羊以及灰鼠的肠毒血症等。D型魏氏梭菌所产的毒素是引起动物死亡的重要因素之一,本文综述了D型魏氏梭菌毒素的结构、功能以及检测方法的研究进展。     

互助县人工草地建设和饲草加工利用现状调查

通过对近年来以项目建设形成的人工饲草地、退耕还草地和以群众根据养殖需要自发种植的饲草地以及饲草加工企业的调查统计，研究分析了互助县目前人工草地建设的发展态势和饲草种植、加工利用当中存在的问题，提出了相应的发展对策建议。     

甘南玛曲七种主要饲草营养价值比较

对甘南玛曲七种主要饲草的干草产量、高度、常规养分(粗蛋白质、酸性洗涤纤维、粗脂肪、粗灰分、无氮浸出物、钙、磷)进行测定,用灰色关联度法对其营养价值进行评价.结果表明:天然草地干草产量为2882kg/hm2,比新疆大叶苜蓿、甘农l号苜蓿、红豆草和箭(苫)豌豆高,比绿麦、燕麦和垂穗披碱草低,牧草营养价值为甘农1号苜蓿＞绿麦＞箭(苫)豌豆＞垂穗披碱草＞新疆大叶苜蓿＞燕麦＞天然草地＞红豆草.     

条带式改良陡坡草地生产性能的研究

本试验对条带式补播改良陡坡草地的生产性能进行了研究。试验根据坡度分为小于25°、25～35°和大于35°的坡地三个处理组。其结果表明,条带式改良草地可以提高产草量,较天然草地三个坡度级分别提高200.39、253.12和203.27%(P<0.01),又可以改善草群品种,豆科牧草分别占总产草量的48.97、72.33和84.14%,且有毒有害植物明显减少。植被盖度由原来的42.5%增加到83.5%,将蒿属植物为建群种的群落变为沙打旺—野艾蒿—万年蓬组成的群落。     

适应河北坝上地区种植的几种牧草

本文根据多年的调查与研究,论述了适应我省坝上地区种植的几种优良牧草。