干旱胁迫条件下不同饲用燕麦品种种子萌发指标比较与评价

本研究采用PEG-6000溶液模拟干旱胁迫条件,比较研究了26份饲草型燕麦(Avena sativa L.)种子的萌发特征,利用主成分分析法和隶属函数法进行了综合评价,为抗旱燕麦品种选育提供实验参考。结果表明,与CK相比,15% PEG浓度下,所有材料的发芽率、发芽势、芽长、根长、种子活力指数等指标均显著下降,不同品种之间差异显著。经主成分分析法筛选,发芽势、发芽指数、活力指数为燕麦种质耐旱性评价的主效指标。通过综合评价,'荟峰’、'三星’、'喜韵’为强抗旱品种;'梦龙’、'大富翁’为中等抗旱品种;'甜燕2号’、'挑战者’、'白燕7号’、'甜燕麦青海’、'甜燕70’、'牧乐思’、'进口甜燕’、'禾王’、'当地燕麦’、'莫尼卡’、'巴燕3号’、'燕麦克劳沃’、'甜燕麦’、'摄政王’、'青海444’为弱抗旱品种;'青牧’、'福燕1号’、'喜越’、'青甜1号’、'甜燕1号’、'shooter’为不抗旱品种。     

低能N+注入紫花苜蓿生物学效应初步研究

对N 注入紫花苜蓿Medicago sativa所引起生物学效应从生理生化层面进行了较系统的研究,结果显示:在低剂量范围内(0~2.08×1016N /cm2),N 注入对紫花苜蓿种子存在当代刺激效应,所研究的几种生理生化指标相对CK都有所提高。剂量为6.24×1016~8.32×1016N /cm2的N 注入对紫花苜蓿种子存在反常辐照损伤效应。即随着N 注入剂量增加,各生理生化指标先降,后升,再降。N 注入使紫花苜蓿过氧化物酶同工酶酶谱发生变异。处理组与对照组扩增出的相同谱带亦存在谱带荧光强度有差异的现象。另外,对N 注入束介导大豆基因组DNA转入紫花苜蓿做了初步研究,结果M2总性状突变率达到19.8%,并得到3株叶片粗蛋白含量较高的突变株(粗蛋白含量比对照高约0.5%)、1株高叶绿素含量的突变株(叶绿素含量比对照高33.3%)。     

长安区不同性质土层CO2释放规律研究

通过对长安双竹村夏、秋季不同性质土层CO2释放量的测定,本文研究了不同性质土层CO2释放规律及其差异。资料表明,从当日早晨到次日早晨,不同性质土层土壤CO2释放量均呈现由低到高再到低的变化规律;土壤CO2释放量与土层性质有密切关系,马兰黄土土层CO2释放量最高,其次是黏性土,释放量最低的是含砾石中细砂土;土层CO2释放量变化与气温的变化呈现负相关。     

土壤—作物资源多目标优化配置分析

本文提出一种多目标土壤—作物资源优化配置的数量化分析方法,并对江苏省东海县土壤资源进行优化配置。结果表明：白浆土、岭砂土、包浆土、紫砂土等岗岭低产土应稳定小麦面积,压缩玉米面积,优先发展春花生、大豆、水稻;洼地砂姜黑土、水稻土应发展小麦—水稻和小麦—玉米两熟制,并适时换茬;介于上述两类土壤间的潮棕壤亚类和潮土类应大力发展小麦—花生两熟制。     

Expression of E‐cadherin in canine anal sac gland carcinoma and its association with survival*

The objective of this study was to determine whether an association could be demonstrated between survival and the expression of the adhesion molecule E‐cadherin by the neoplastic cells in a group of dogs with anal sac gland carcinomas (ASGCs). Archived formalin‐fixed, paraffin wax‐embedded primary tumour specimens were obtained for 36 cases of canine ASGC with known clinical management and survival data. Immunohistochemical methods were used to evaluate E‐cadherin expression by the neoplastic cells and data were evaluated for an association between E‐cadherin expression and survival. On univariate analysis, the median survival time for cases with tumours expressing E‐cadherin in more than 75% of cells was significantly greater than that for cases with tumours expressing E‐cadherin in fewer than 75% of cells (1168 versus 448 days, P = 0.0246). Both E‐cadherin expression and presence or absence of distant metastases were significantly associated with survival on multivariate analysis. This study demonstrates that expression of E‐cadherin at the cytoplasmic membrane in canine ASGCs is variable and potentially predictive of survival.     

陕北水蚀风蚀交错区苜蓿地土壤水分过耗与恢复

采用野外定位观测法研究水蚀风蚀交错区苜蓿(Medicago sativa)草地土壤水分在天然降水作用下的恢复过程。结果显示:苜蓿地翻耕后,在降水作用下土壤水分有明显的恢复过程,第一年,150cm以上土壤水分得到一定恢复,第二年深度达到300cm,但上层土壤含水量并未增加;该地块植被大量消耗土壤储水导致土壤干燥化,高耗水植被消除后,土壤含水量逐渐增加。     

BPI指数在西杂牛经济类型划分上的应用研究

[目的]进一步提高我区西杂牛的选育水平,为培育河西肉牛新类群提供理论依据。[方法]通过采用BPI指数法,对172头西杂牛的测定分析。[结果]一岁公牛BPI指数平均为6.81±1.24、二岁公牛为7.14±1.38、三岁公牛为5.58±1.47,均达到或超过5.9的肉用型指标;一岁母牛BPI指数平均为4.45±1.07、...     

中草药添加剂对育肥猪生长性能及血液生化指标的影响

将120头胎次、日龄相近,体质量在70kg左右的＂杜×长×大＂三元杂交猪随机分为4组,空白对照组只饲喂基础饲粮,西药组添加0.02%半胱胺,其他2组分别添加1%和0.5%的中草药添加剂。结果表明：在生长性能方面,2个中药组（B、C组）、半胱胺组（D组）的日增重分别比空白对照组（A组）提高了9.89%（P〈0.05）,4.42%（P〉0.05）和1.26%（P〉0.05）,料肉比分别比对照组降低了7.07%（P〈0.05）,4.49%（P〈0.05）和3.97%（P〈0.05）;添加中草药添加剂,对猪只肝肾功能无不良影响。     

Phytomass estimation using eMODIS NDVI and ground data in arid rangelands of Morocco

The assessment of rangeland productivity in semi-extensively grazed arid rangelands is a prerequisite for livestock management in relation to sustainable use of pastoral resources. The objective of this study was to assess rangeland productivity based on normalised difference vegetation index (NDVI) images. Data on phytomass were measured on 61 field samples in arid rangelands of Morocco, covering various rangeland categories during autumn (November) and spring (April), i.e. when phytomass is at low and high levels, respectively, for two consecutive years (2008 and 2009). Dekadal EROS Moderate Resolution Imaging Spectroradiometer (eMODIS) NDVI data were linearly regressed to field measurements for these four periods. Results show that phytomass values were correlated with NDVI during spring, with R² and RMSE values of 0.82 and 0.3 t ha^?1, respectively. This study indicates there is a high potential for operational use of remotely sensed data to estimate rangeland phytomass of semi-extensively grazed rangelands.     

遮阴对成坪期草地早熟禾和紫羊茅生长特性的影响

以冷季型草坪草草地早熟禾(Poa pratensis)的优异(Merit)、新哥来德(Nu Glade)、肯塔基(K.B.G)3个品种和紫羊茅(Festuca rubra)的两个品种宝瑞(Boreal)、梦神(rubra),共5个品种草坪草为研究对象,在人工遮阴控制下,对其成坪期耐阴性进行了比较。试验设置的遮阴处理分别是遮阴度22%、45%、66%、83%,以不遮阴的全光照为对照(CK)。结果表明,成坪期,随着遮阴度的提高,株高先增加后降低,各品种株高值达到最高时的遮阴度有差异,草地早熟禾在遮阴度为83%时均显著低于其他处理(P0.05);宝瑞在遮阴度为22%时根长极显著高于对照(P0.01),其他品种随着遮阴度的提高根长变短;遮阴使各品种的比叶重降低;遮阴度45%以上时,叶宽都显著小于对照(P0.05);随着遮阴度提高草地早熟禾枝条干重下降,紫羊茅先增加后降低。