烟草黑胫病和根黑腐病生防假单胞杆菌的筛选与鉴定

为获得对烟草黑胫病和根黑腐病具有双重防病效果且能够促进烟草生长的假单胞杆菌,采用稀释涂布法从40份土壤样品中分离出201株细菌,通过平板对峙和含毒介质法,筛选出对烟草黑胫病和烟草根黑腐病病原菌均具有良好拮抗作用的菌株PA2101和PG3402。盆栽促生试验表明,菌株PA2101和PG3402能协调地改善烟草地上部分的生长和烟草根系发育,均在一定程度上增加了烟草的株高、叶面积、株鲜重、根鲜重、叶片数和根长,提高了烟草的根冠比和根活力。盆栽试验结果表明,菌株PA2101对烟草黑胫病和根黑腐病的防效分别为70.11%和62.67%,均高于其对照药剂;菌株PG3402对两种病害的防效分别为60.92%和60.00%,与对照药剂相当。抗性标记菌株的定殖试验结果表明,菌株PA2101和PG3402在接种后第29 d能定殖于烟草根际土壤和根内,在烟草茎和叶内也能长时间存在,表明两菌株能够良好定殖。16Sr DNA序列、菌落形态和生理生化性状分析表明,菌株PA2101为铜绿假单胞杆菌Pseudomonas aeruginosa,菌株PG3402为格拉纳达假单胞杆菌Pseudomonas granadensis。综上所述,菌株PA2101和PG3402对烟草具有良好的促生作用,并对烟草黑胫病和根黑腐病有较好的防病效果,是具有生防潜力的菌株。     

橡胶树中碱性转化酶HbNIN9表达及酶学特性分析

转化酶作为蔗糖分解代谢的关键酶,在植物生长发育、生物与非生物胁迫响应等生理过程中发挥重要作用。基于对橡胶树不同组织转录组数据库的分析,本研究克隆了一个在橡胶树种子中有较高丰度表达的中碱性转化酶基因HbNIN9;系统进化分析和在线软件预测均显示其亚细胞定位为线粒体,属于中碱性转化酶α亚族成员;利用原核表达体系成功获得Hb NIN9优化表达的重组蛋白,优化表达的诱导条件为0.5 mmol/L IPTG,25℃培养6 h;酶学特性分析表明,HbNIN9蛋白酶活反应的最适温度为45℃,最适pH值为7.5,米氏常数Km值为18.09 mmol/L。本研究从蛋白水平证实了Hb NIN9为典型的中碱性转化酶,有助于深入揭示线粒体型转化酶在橡胶树种子糖代谢中生理功能,丰富橡胶树中碱性转化酶家族成员的生理生化研究。     

基于DUS测试的上海地区小麦新品种评价

本研究通过分析小麦DUS测试指南中标准品种、测试性状在上海地区的表达差异,评价小麦DUS测试指南在上海的适应性,同时对15个引进品种及9个申请审定的品种在上海的表现进行评价。通过2016-2017年的田间种植试验,用符合系数对标准品种和测试性状在上海地区的性状表现与小麦测试指南中的代码进行了差异性分析,并对性状间的相关性进行了分析。结果表明,小麦测试指南中的33个测试性状中有8个性状的符合系数为1,占24.2%,数量性状的表现受环境条件的影响较大,符合系数小于0.9的2个性状都是数量性状;小麦测试指南中的42个标准品种中有21个品种的符合系数为1,其性状表达状态非常稳定。‘矮变1号’的符合系数最低,其次是‘川育6号’、‘济南16号’、‘科麦2号’,其他品种的符合系数均大于0.95。大部分品种可以作为标准品种应用于上海地区的小麦DUS测试。‘植株:高度’与多个性状存在显著相关性,3个蜡质性状间相关程度较高。‘籽粒:大小’与指南中的7个性状显著相关。引进品种在上海地区的表现较好,均具备一致性,亲缘关系较近。待审定品种‘润麦1号’表现优于所有参试品种。     

耐低温弱光网纹甜瓜新品种‘西蜜6号’

‘西蜜6号’网纹甜瓜为杂交一代新品种。果实长椭圆形,单果质量1 000 ~ 1 300 g。果皮黄绿色,果面覆网纹,网纹细、稍稀、均匀。果肉橘色,厚3.8 cm,中心可溶性固形物含量15%,果肉脆。生育期100 ~ 102 d,果实发育期40 ~ 42 d。产量40 000 ~ 45 000 kg · hm^-2。耐低温弱光,较抗霜霉病和白粉病,耐贮运。     

杜仲胶实验室提取方法的研究

提取杜仲药用成分后的叶渣,分别用发酵法、甲苯浸提和碱浸３种方法提取杜仲胶,并对碱浸法碱的浓度、浸提温度和浸提次数进行了比较试验。结果以碱浸法用１０％碱液在９０℃温度下,连续提取２次,浸提物再用浓盐酸处理２ｈ,分解除去粗胶中的非胶部分,效果较好。     

Effects of total replacement of fish oil by pork lard or rapeseed oil and recovery by a fish oil finishing diet on growth,health and fish quality of gibel carp (Carassius auratus gibelio)

An 84‐day growth trial was designed to investigate effects of dietary replacements fish oil with pork lard (PL) or rapeseed oil (RO) on growth and quality of gibel carp (Carassius auratus gibelio var. CAS III) (initial body weight: 158.2 ± 0.2 g), and responses of the fish refed fish oil (FO) diet. Three isonitrogenous (crude protein: 30%) and isolipid (crude lipid: 10%) diets were formulated containing 7.73% FO, PL or RO. Five experimental treatments including FO group (FO), PL group (PL), RO group (RO), group fed PL for 42 days and refed FO for 42 days (PL+rFO), RO and refed FO group (RO+rFO) was tested. At the end of first 42 days, the fish fed PL and RO had higher mortality than that of the control (P > 0.05). At the end of whole experiment, fish fed PL and RO showed higher plasma cortisol than FO fish (P < 0.05). RO+rFO fish showed higher lysozyme activity than RO fish (P < 0.05). Fish growth and feed utilization, composition of whole body and muscle, free amino acids, texture, off‐flavour substances or sensory attributes were not affected by dietary treatments (P > 0.05). PL and RO diet decreased muscle EPA, DHA and n‐3/n‐6 ratio (P < 0.05), while FO‐refeeding had recovery effect. It can be concluded that the replacement of FO by PL and RO does not affect the growth, feed utilization or fish tasting quality in gibel carp. Fish muscle fatty acids modified by dietary PL and RO can be recovered by refeeding with FO diet.     

Effects of dietary vitamin C on growth,gonad development and antioxidant ability of on‐growing gibel carp (Carassius auratus gibelio var. CAS III)

An 88‐day experiment was conducted in a flowing system to evaluate the effects of dietary vitamin C on growth, body composition, antioxidant and gonad development of on‐growing gibel carp. Triplicate tanks of gibel carp (77.2 ± 0.1 g) were randomly fed with one of seven experimental diets containing l ‐ascorbic acid of 0, 101.1, 188.5, 313.1, 444.1, 582.1 and 747.0 mg/kg, respectively. The results showed that specific growth rate (SGR) and feed efficiency (FE) of fish were not affected by dietary l ‐ascorbic acid. Dietary l ‐ascorbic acid of 444.1 mg/kg diet led to low levels (p < .05) of gonadosomatic index (GSI) and hypothalamic gonadotropin‐releasing hormone (GnRH) in on‐growing fish, as well as the early ovarian stages (Developing stages) compared with fish (Maturing stages) from the other groups. Dietary l ‐ascorbic acid supplementation increased (p < .05) the dorsal muscle collagen content, but did not affect the protein or lipid content of dorsal muscle in gibel carp. Plasma total antioxidant capacity (T‐AOC) and superoxide dismutase (SOD) activity increased (p < .05) and then remained unchanged with the increase in dietary l ‐ascorbic acid levels. Dietary l ‐ascorbic acid of 101.1 mg/kg diet improved (p < .05) plasma lysozyme activity of the fish. Broken‐line regression indicated that dietary l ‐ascorbic acid requirement of 77 g gibel carp was 223.3 or 225.0 mg/kg diet based on plasma T‐AOC or SOD activity, which was a little higher than that based on plasma l ‐ascorbic acid concentration (193.2 mg/kg).     

Regulations on glucose metabolism affected by dietary carbohydrate in different strains of juvenile gibel carp (Carassius gibelio)

This experiment was conducted to study the effects of dietary carbohydrate on glucose metabolism in gibel carp (Carassius gibelio) as well to investigate if different clones had different responses to carbohydrate intake. Unselected Dongting strain (DT strain), selected gibel carp “CAS III” (A strain) and gibel carp “CAS V” (F strain) were fed with no corn starch diet (0C), 30% corn starch diet (30C) and 45% corn starch diet (45C) for 8 weeks. The results showed that selected F strain showed higher growth performance. F strain and A strain showed better control on postprandial glucose regulation by increasing plasma triglyceride, plasma cholesterol, liver and muscle glycogen contents and also enhancing glycolysis and restraining gluconeogenesis. DT strain had higher body lipid and lipid utilization. In conclusion, gibel carp could tolerate 45% dietary carbohydrate and F strain showed better growth by increasing glycolysis while decreasing glycogenesis.     

番茄抗黄化曲叶病毒育种研究进展

本文分别对近年番茄抗黄化曲叶病毒的传统育种、分子辅助育种、基因工程育种进展进行了综述。栽培番茄均不抗番茄黄化曲叶病毒,所以传统育种采用从野生近缘种中筛选抗性材料,以其为亲本与栽培番茄进行杂交来获得抗性;野生近缘种中的抗性位点Ty-1、Ty-2和Ty-3及一些QTLs先后被定位,也筛选出了可鉴定巩一,基因的SSR-47标记及鉴定Ty-3的SCAR标记;通过转基因技术获得抗性是研究热点之一,目前转入番茄后表现出抗性的序列有TYLCV病毒的CP基因、REP基因的部分序列或反义序列、不编码的保守序列以及源于白粉虱的GroEL基因。同时讨论了今后的主要发展方向。