黄瓜雌雄株性别苗期化学鉴别方法

应用BTB(溴麝香草酚蓝 )法、NADH(还原辅酶Ⅰ )法和TTC(氯化三苯基四氮唑 )法对黄瓜雌雄株进行了苗期鉴别 ,结果表明 :雌、雄株提取液加入BTB液后雌株转色快于雄株 ,反应后 5h(小时 )内在 6 30nm处雌、雄株吸光值差异最大 ,是鉴别黄瓜雌、雄株的最佳时期。雌、雄株NADH含量和TTCH含量差异显著。BTB法、NADH法和TTC法鉴别雌雄株其差异显著概率均为极显著 ,BTB法和TTC法对雌、雄株混合群体的鉴别正确率均为 10 0 % ,二者可应用于黄瓜雌、雄株苗期鉴别。而NADH法对混合群体的鉴别正确率仅 71.4%。     

转基因水稻对稻瘟病的抗性研究

 采用苗期初筛、复筛、抗谱测定和田间自然诱发试验等不同鉴定方法,对经分子检测证明已整合有碱性几丁质酶基因和β-1,3-葡聚精酶基因的22个转化系的转基因水稻植株进行稻瘟病抗性鉴定研究,筛选出对稻瘟病的抗性比原种对照七丝软占有明显提高的一系列转基因水稻品系,其中表现高抗的有来自F4-9转化株系的7个品系。高抗材料的R7代品系,经室内抗谱测定及田间病圃试验结果,仍然表现高抗稻瘟病。本研究通过转基因技术,成功地将优质感病品种改良成高抗品系,研究结果证明了利用基因工程手段培育抗病水稻新品种是一个非常有希望的育种途径。     

寄主植物对桃蚜羧酸酯酶和乙酰胆碱酯酶的诱导作用

在１９９５～１９９６年研究了寄主植物对桃蚜［Ｍｙｚｕｓｐｅｒｓｉｃａｅ（Ｓｕｌｚｅｒ）］羧酸酯酶（ＣａｒＥ）和乙酰胆碱酯酶（ＡＣｈＥ）的诱导作用。在试验的甘蓝、茄子和桃树３种寄主植物中，取食甘蓝的桃蚜种群ＣａｒＥ和ＡＣｈＥ活性最高，取食茄子和桃树的桃蚜种群ＣａｒＥ活性没有明显不同，而ＡＣｈＥ活性取食茄子的桃蚜种群明显高于取食桃树的种群。ＣａｒＥ与底物的亲和力是桃树＞茄子＞甘蓝，而ＡＣｈＥ与底物的亲和力则是甘蓝＞茄子＞桃树。ＡＣｈＥ与毒扁豆碱的双分子速率常数（Ｋｉ）值大小顺序为甘蓝＞桃树＞茄子     

甘肃河西地区盐碱地野生药用植物资源

甘肃河西地区盐碱地野生药用植物资源丰富,主要有50种,隶属于21科40属。针对当地农业生产状况,应合理开发利用盐生药用植物资源。     

南昌市郊常见花卉炭疽病初步鉴定

本文对南昌市郊常见花卉炭疽病病原进行了初步鉴定。结果表明，鹅掌柴炭疽病等8种炭疽病病原为胶孢炭疽菌（Colletotrichum gloeosporioides(Penz.Sacc.)，月季炭疽病等5种病害病原为新报道的炭疽病，病原种的归属有待进一步确定。     

Transgenic cucumber expressing an endogenous class III chitinase gene has reduced symptoms from Botrytis cinerea

A class III chitinase gene (CHI2) is induced in cucumber plants (Cucumis sativa L.) in response to infection by pathogenic microorganisms. Infection of Botrytis cinerea, causal agent of gray mold disease on cucumber, also induces CHI2 expression. To investigate whether CHI2 is involved in resistance to gray mold disease, transgenic cucumber plants were produced to overexpress the CHI2 gene. One line was analyzed in detail in terms of disease resistance. The transgenic cucumber plant (CC2) constitutively expressed CHI2 and reduced the symptoms of B. cinerea for 4 days after inoculation compared with nontransgenic plants. However, this inhibitory effect was not absolute, and CC2 eventually developed serious disease symptoms. Chitinase activity of the crude extract from CC2 leaves was higher than that from nontransgenic plants. A high-molecular-weight fraction containing CHI2 from CC2 leaves had fungistatic activity against B. cinerea. Interestingly, the low-molecular-weight fraction from CC2 leaves with CHI2 removed also had fungistatic activity against B. cinerea. Not only the introduced chitinase activity but also the endogenous defense reactions activated by overexpression of CHI2 may be involved in the enhanced gray mold disease resistance in CC2.     

Recovery of non-target plants affected by airborne bromoxynil-octanoate and metribuzin

The present study was conducted to evaluate the recovery potential of non‐target plants affected by two airborne herbicides. Sunflower at the two‐leaf stage was used as a test plant and exposed for 24 h in a wind tunnel to a range of concentrations of airborne bromoxynil‐octanoate and metribuzin. Quantum yield (φ_PSII) of exposed leaves and of the second leaf pair developed after exposure was determined at a particular time up to 16 days following exposure. Maximum depression in quantum yield of exposed leaves from which a complete recovery occurred within 16 days was 63% for bromoxynil‐octanoate and 60% for metribuzin respectively. The corresponding maximum concentrations were 1.310 and 0.390 μg m^?3 respectively. The second leaf pair was also affected and showed a similar recovery potential. From the results it can be concluded that the significance of airborne bromoxynil‐octanoate and metribuzin must not be overestimated, as sunflower and non‐target plants with a similar sensitivity are likely to recover from air concentrations of both herbicides reported under field conditions.     

复方中草药"毒菌杀"对禽大肠杆菌及鸡白痢沙门氏菌的体外抑菌试验

观察了复方中草药“毒菌杀”的安全性及其对禽大肠杆菌及鸡白痢沙门氏菌的体外抑菌情况。结果发现“毒菌杀”安全性高，组成“毒菌杀”的各单味中药及其合剂对大肠杆菌的最低抑菌浓度MIC(g/mL)分别为板蓝根0．05、穿心莲0．05、黄芪0．025、黄柏0．05、柴胡0．05、生地0．05、甘草0．05、当归0．025，“毒菌杀”方剂为0．05；对沙门氏菌的MIC分别为板蓝根0．05、穿心莲0．025、黄芪0．025、黄柏0．05、柴胡0．025、生地0．05、甘草0．025、当归0．05，“毒菌杀”方剂为0．025；而牛胆汁对这两种致病菌的最低抑菌浓度分别为2％和1％。说明“毒菌杀”方剂对大肠杆菌、沙门氏菌具有明显的抑制作用。     

川西北高寒沙地不同年限高山柳林下优势植物碳、氮、磷生态化学计量特征

通过采集川西北高寒沙地不同年限(6、18、24年)高山柳林下3种优势植被藏沙蒿、裂叶独活和镰荚棘豆,分别测定分析3种植被叶片、根部C、N、P化学计量特征变化特征。结果表明:不同年限高山柳林下植被C、N、P含量及其比值间存在显著差异且呈现出不同变化趋势。林下植被C含量整体下降;叶N含量呈上升趋势,根N含量随年限增长而下降;除藏沙蒿外,林下植被P含量变化不显著;C∶N变化范围为1.92~12.86;C∶P为29.18~196.88;不同年限高山柳林下植被N∶P间虽存在差异,但均表现出主要受到P限制,表明该区域植被生长主要受P限制,应注意P养分的适当补充。     

Performance,rumen fermentation and blood metabolites of dairy calves fed starter mixtures supplemented with herbal plants,essential oils or monensin

This study evaluated the supplementation effects of three herbal plants (thyme [THY], eucalyptus [EUC] and celery [CEL]), a commercial phytogenic additive ?containing essential oils (PFA‐EO, Digestarom^® P.E.P.) and monensin (MON) in calf starter on performance, rumen fermentation and blood metabolites during pre‐ (days 3–55) and post‐weaning (days 56–70). Sixty‐six Holstein dairy calves (3 days of age, 41.2 ± 3 kg of BW) were allocated to one of six starters supplemented with: (i) no additives (CON), (ii) MON (30 mg/kg), (iii) THY (23 g/kg), (iv) CEL (23 g/kg), (v) EUC (23 g/kg) and (vi) PFA‐EO (3 g/kg). All the calves were offered starters ad libitum plus 6 L of whole milk daily. Starter intake tended to be the highest in calves fed PFA‐EO and THY; intermediate in calves fed CON, MON and EUC; and the lowest in those fed CEL. Average daily gain (ADG) and feed efficiency (FE) remained unaffected by dietary treatments during the pre‐weaning. During the post‐weaning period, ADG and FE ?were greatest in calves fed EUC followed by those fed CON, MON, PFA‐EO and THY, and then in those fed CEL. No differences were observed among the treatments in skeletal growth, faecal score, rumen pH or ammonia‐N concentration. Compared to calves fed CON and MON, those fed the herbal plants or PFA‐EO tended to recorded higher molar proportions of acetate and butyrate, and the acetate: propionate ratio. Blood malondialdehyde level did not differ among treatments, but calves on CON had the highest glucose concentration, and those fed PFA‐EO recorded the highest value for β‐hydroxyl butyrate on day 70. In conclusion, the results indicate that the three herbs and PFA‐EO are capable of modulating some of the rumen fermentation parameters and blood metabolites as well as eucalyptus could potentially be a better alternative to monensin for improving post‐weaning performance.