养殖中国水蛇适温性研究

通过对中国水蛇生长率与死亡率的测定,研究了水温与中国水蛇生长和生存的关系。结果显示：整个过程,特定生长率（S）与水温（T）存在极显著的二次多项式函数关系S=0．0021 T^2-0．0748 T＋0．7984（R^2=0．8475,P〈0．01）;在高温与低温条件下,水温与死亡率（D）均存在显著的二次多项式函数关系,分别为难-0．0349／92＋0．8345 D＋28．895（R^2=0．763,P〈0．01）和T=0．0069 D^2-0．4007 D＋13．621（R^2=0．612,P〈0．05）。结果表明,中国水蛇适宜生长水温范围17．81～31℃,最适生长水温范围26～30℃,能耐水温上限31～33．88℃,能耐水温下限7．80～10℃。该研究为今后中国水蛇规模化养殖提供技术参考。     

60Co-γ射线辐照对黄牡丹种子萌发及幼苗生长的影响*

  对黄牡丹种子进行不同剂量的60Co-γ射线辐照处理,以未照射种子为对照, 观测辐照对种子生根、萌发及幼苗生长的影响。结果表明:种子生根率和萌发率随辐照剂量增加而降低,高剂量(100Gy以上)对种子萌发和幼苗生长有显著的抑制作用（P<005）,辐照的剂量与幼苗存活率呈负相关,且幼苗表型性状各不相同。根据试验数据以及回归分析确定黄牡丹种子的临界剂量为485Gy,适宜剂量范围为40～60Gy。     

Risk Assessment and Biosafety Studies of Transgenic Bt Rice （Oryza sativa L.）

Transgenic crops having alien genes from different sources are getting popularity. A Rice （Oryza sativa L.） containing gene from Bacillus thuringiensis, a soil bacterium, was assessed to study the potential risks of transgenic plants on environment. The crop was found resistant to target insect pests. Rice variety Basmati-370 transformed with two insecticidal genes, crylAc and cry2A, was grown under field conditions for several years. Data were collected at different stages of the plant growth. Fate of Cry protein in soil, effect of Bt protein on non-target insects, risks of vertical and horizontal gene flow were evaluated. No potential hazard was found at all levels. Bt protein was unstable and degraded significantly in soil within 30 days after harvesting the crop. No harmful effects were found on non-target insects （insects other than order lepidoptera）. Maximum gene flow of 0.02% was observed at close spacing and no evidence of horizontal gene transfer to Rhizobium spp. was found. In conclusion, the transgenic rice plants transformed with Bt genes have no harmful effects on the environment.     

Effects of Gradual Water Deficit Stress on Phenological and Morphological Traits in Chickpea （Cicer arietinum L.）

The aims of this study were to investigate the effect of gradual water deficit stress on some phonological and morphological traits and grain yield of desi and kabuli chickpea cultivars. This study was carried out in 2007 and 2008, to evaluate responses of three chickpea cultivars （Hashem and Arman from kabuli and Pirooz from desi type） under well watering （I1： 70mm evaporation from class A pan）, gradual water deficit （12 and 13： 70→90→ 110→130 and 70→100→130mm evaporation from class A pan, respectively） and severe water stress （14： 130mm evaporation from class A pan）. Result showed that days to flowering and plant height were decreased, as water limitation increased. This reduction was significant under gradual water stress （I2 and I3） and Severe water deficit （I4）, compared with control （I1）. There were no significant differences in grain filling period and grain yield among I~, I2 and I3 irrigation treatments. No significant differences in days to physiologic maturity and number of sub branches were recorded among irrigation treatments. Interactions of year×cultivar for days to physiologic maturity, grain filling period and grain yield （P≤0.01） and for days to flowering and plant height （P≤0.05） were significant. The superiority of Arman in producing comparatively greater grain yield could be attributed to higher grain filling period of this cultivar in both years.     

飞机草各组分的化感作用研究

化感作用在生物入侵过程中具有重要的意义,飞机草具有化感作用,为研究其入侵性,实验对飞机草的各组分进行生物化感测定。结果表明,飞机草中的化感物质主要存在于石油醚和氯仿俩组分,对萝卜和菜心试验作物的幼苗生长有明显的抑制作用,而且抑制作用随着浓度的提高而增强,尤其体现在对作物的根长抑制上,在浓度2mg/ml时抑制率就达到80%,在4mg/ml时抑制率达到90%。2mg/ml水提物组分则是起到略微促进生长作用。     

北部湾4个自然群体双线紫蛤形态差异与判别分析

采用3种多元分析方法,对北部湾4个海区双线紫蛤的7个形态性状进行比较研究。聚类分析和主成分分析结果表明,广西钦州和广西北海群体形态最为接近,广西湛江与广东廉江群体形态比较接近,广西北海和广东廉江群体的趋异程度最大。主成分分析表明3个主成分的贡献率为:主成分1为38.395%,主成分2为27.653%,主成分3为20.224%,累积贡献率为86.272%。判别分析结果表明,4个群体间形态差异显著(P<0.01),建立的判别函数的判别准确率P1和P2均为73.30%~90.00%,综合判别率为79.18%。相关分析发现,双线紫蛤群体间的欧氏距离与地理距离之间有一定相关性,相关系数r=0.669 9。     

柱头外露棉花器形态与育性类型的关系研究

大田条件下观察柱头外露棉雌雄蕊外部形态特征,并调查分析花柱类型与花器官长度的关系。结果表明,可将柱头外露棉育性分为四大类：可育、半可育、败育和不育。     

树皮堆肥施用方法对番茄生长、产量及品质的影响

在日光温室栽培条件下,研究了树皮堆肥对番茄生长、产量及品质的影响。结果表明,与施用普通有机肥相比,施用树皮堆肥可促进番茄植株的生长,提高根系活力和净光合速率,增加产量,改善果实营养品质和风味,尤可增加VC含量和可溶性糖含量,减少果实硝酸盐含量,其中666．7m2穴施5000kg树皮堆肥处理效果最好。     

钾对NaCl胁迫下玉米幼苗保护酶活性等生理特性的影响

采用水培法研究了不同浓度钾对盐胁迫下玉米幼苗生长、叶绿素含量、细胞膜透性及保护酶活性等生理特性的影响。结果表明适量的增加K+供应能有效促进玉米生长,抑制叶绿素含量降低,降低细胞膜透性,提高玉米叶片和根系中的SOD、POD和CAT活性增加。表明盐胁迫下供钾充足,可以增加玉米幼苗叶片和根系中保护酶活性,提高玉米幼苗的耐盐性。     

长白柳种质试管保存研究

[目的]筛选出长白柳嫩茎离体培养各阶段的培养基。[方法]以长白柳嫩茎基部直接再生形成的丛生芽团为试材,利用＂延缓生长＂的方法在试管内对长白柳进行种质保存,应用均匀设计法探讨了影响长白柳丛生芽团试管保存的主要因子和水平,筛选最适于长白柳丛生芽团试管保存的培养基。[结果]长白柳最适宜的丛生芽团试管保存培养基为：N-68＋根皮苷3.20 mg/L＋KT0.70 mg/L,保存43个月生长率仅为0.97%。对保存前后的芽苗生根情况对比结果表明,保存后的芽苗生根速度快,生根率达99.6%以上,较未保存前的生根率99.0%高。[结论]在试管内采取＂延缓生长＂法保存长白柳丛生芽团是切实可行的新方法。