套作春玉米氮磷钾化肥和有机肥合理配比的生产函数分析

采用田间试验的方法，对苏南地区麦玉米稻三热制中套作春玉米的合理施肥量肥料配比进行了研究。     

人工卵饲养中华草蛉幼虫研究初报

用啤酒酵母、大豆、牛肉水解物为主的饲料,制成蜡壳人工卵饲养中华草蛉(Chrysopa sinica)幼虫可以完成发育,但与用米蛾卵饲养的处理比较,幼虫历期延长,茧重减轻;对蛹历期、成茧率、羽化率、性比、产卵前期均无显著影响。将饲料制成人工卵的饲养结果比用泡沫塑料吸附法显著为好。部分龄期喂人工卵的比全幼虫期喂人工卵的影响为轻,一、二龄喂米蛾卵,三龄喂人工卵的处理,虽然对蛹重仍有影响,但在幼虫发育历期和成虫获得率上与全幼虫期喂米蛾卵的差异不显著。全幼虫期或部分龄期喂人工卵和全幼虫期喂米蛾卵饲养出来的草蛉成虫用啤酒酵母干粉作成虫饲料,30天内的产卵量差异不显著。据生防室以前的试验,三龄幼虫取食的米蛾卵量占全幼虫期总取食量的76%,因此一、二龄喂米蛾卵,三龄喂人工卵既不影响草蛉的繁殖力,又可节省大量米蛾卵,在生产实践上有应用价值。     

Effects of Moringa oleifera silage on milk yield,nutrient digestibility and serum biochemical indexes of lactating dairy cows

This study investigated the effects of Moringa oleifera (MO) as a partial substitute of alfalfa hay on milk yield, nutrient apparent digestibility and serum biochemical indexes of dairy cows. MO was harvested at 120 days post‐seeding. Fresh MO was cut, mixed with chopped oat hay (425:575 on a DM basis), ensiled and stored for 60 days. Sixty healthy Holstein dairy cows were allocated to one of three groups: NM (no MO or control), LM (low MO; 25% alfalfa hay and 50% maize silage were replaced by MO silage) or HM (high MO; 50% alfalfa hay and 100% maize silage were replaced by MO silage). The feeding trial lasted 35 days. The LM and HM diets did not affect dry matter (DM) intake, milk yield or milk composition (lactose, milk fat, milk protein and somatic cell count). The apparent digestibility of DM and NDF was lower for HM group than NM group. Additionally, there were no significant differences in serum biochemical indexes between the LM and NM groups. The HM group had lower serum concentrations of total cholesterol, high‐density lipoprotein cholesterol, and low‐density lipoprotein cholesterol and higher serum concentrations of urea than the NM group. The partial replacement of alfalfa hay (≤50%) and maize silage with MO silage had no negative effects on milk yield, in vivo nutrient apparent digestibility or serum biochemical indexes of lactating cows.     

三个牦牛品种生长激素受体(GHR)基因PCR-SSCP分析

为了加速牦牛群体的复壮,本实验利用PCR-SSCP技术对甘南、天祝、青海高原3个牦牛品种的生长激素受体基因进行了多态性分析。结果表明:第1、3对引物扩增无多态,第2对引物扩增3个牦牛品种均发现2个等位基因A和B,天祝白牦牛A的基因频率为0.3682,B的基因频率为0.6318;甘南牦牛A的基因频率为0.1596,B的基因频率为0.8404;高原牦牛A的基因频率为0.0700,B的基因频率为0.9300。青海高原牦牛群体处于哈代-温伯格平衡状态,而甘南和天祝牦牛处于不平衡状态,应加强对该基因位点的选择强度。     

节能日光温室番茄长季节高产栽培研究初报

对日光温室番茄长季节栽培进行了品种筛选及施肥指标和环境调控的研究 ,筛选出适宜日光温室番茄长季节栽培的品种 4个 ,提出 6 6 7m2 产量 2 0 0 0 0kg番茄的复合肥和钾肥施肥指标及采用遮阳网、反光幕、防虫网、诱虫色板、膜下滴灌等环境调控技术和措施。     

β-carotene attenuates weaning-induced apoptosis via inhibition of PERK-CHOP and IRE1-JNK/p38 MAPK signalling pathways in piglet jejunum

Weaning may cause oxidative injury, immune response impairment, apoptosis and other injuries in piglets. Oxidative and endoplasmic reticulum stress (ERS) can elicit inflammatory responses, and persistent oxidative and ERS also may lead to apoptotic cascades, which is associated with the pathogenesis of multiple diseases. β-carotene, a natural carotenoid, has potential anti-inflammatory and antioxidant functions. However, the effect of β-carotene on apoptosis in weaned piglets and the detailed molecular mechanism remain unclear. In this study, we found that β-carotene decreased malondialdehyde (MDA) levels and increased the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in piglet serum. β-carotene could inhibit the mRNA levels of caspase-3 significantly, but had no significant inhibitory effect of the mRNA levels of caspase-9 and caspase-12 in the piglet jejunum. In addition, β-carotene decreased the activation of GRP78, CHOP, and JNK/p38 MAPK and the ratio of Bax/Bcl-2. Furthermore, β-carotene had a significant influence on the activation of ERS and apoptosis-related signals in TG-induced IPEC-J2. In the present study, β-carotene pre-treatment attenuated the ratio of Bax/Bcl-2 and prevented TG-induced increases in the level of PERK-CHOP and IRE1-JNK/p38 MAPK pathway activation in a dose-dependent manner. Overall, these findings indicate that β-carotene may protect weaning-induced apoptosis through inhibiting ERS.     

Factors affecting the virulence of Ralstonia solanacearum and its colonization on tobacco roots

Tobacco bacterial wilt caused by Ralstonia solanacearum is a serious disease affecting tobacco cultivation in southwest China. The response surface methodology was employed to evaluate the optimal conditions of tobacco bacterial wilt, and green fluorescent protein gene (gfp) labelling was applied to monitor the location and survival dynamics of R. solanacearum (Rs::gfp) on tobacco roots and in soil under these optimal conditions. The results showed that the highest wilt incidence was 91.13%, which occurred when the population reached 6.6 × 10⁶ CFU/g soil, the temperature was 30.55 °C, and the humidity was >81.42%. The Rs::gfp densely colonized the root tips and root hairs, and cells of Rs::gfp were observed intermittently in the elongation zone or at the point of the emerging lateral roots. The Rs::gfp number in the rhizosphere soil was 10.75‐, 73.13‐ and 74.86‐times higher than that in the bulk soil at 10, 15 and 20 days after transplantation, respectively. Increased colonization by Rs::gfp was related to the population of the pathogen, the environmental temperature and the humidity in the soil. These three conditions determined whether R. solanacearum would induce tobacco wilt. This is the first study to investigate factors affecting the virulence of a tobacco wilt bacterial pathogen, which is important for conducting field diagnosis and biocontrol of tobacco bacterial wilt.     

Effects of concentrate‐to‐forage ratios and 2‐methylbutyrate supplementation on ruminal fermentation,bacteria abundance and urinary excretion of purine derivatives in Chinese Simmental steers

This study evaluated the effects of dietary concentrate levels and 2‐methylbutyrate (2MB ) supplementation on performance, ruminal fermentation, bacteria abundance, microbial enzyme activity and urinary excretion of purine derivatives (PD ) in steers. Eight ruminally cannulated Simmental steers (12 months of age; 389 ± 3.7 kg of body weight) were used in a replicated 4 × 4 Latin square design with a 2 × 2 factorial arrangement. Moderate‐concentrate (400 g/kg diet [MC ]) or high‐concentrate (600 g/kg diet [HC ]) diets were fed with or without 2MB (0 g/day [2MB ?] or 15.0 g/day [2MB +]). Dry matter intake and average daily gain increased, but feed conversion ratio decreased with the HC diet or 2MB supplementation. Ruminal pH decreased, but total volatile fatty acid increased with the HC diet or 2MB supplementation. Molar proportion of acetate and acetate‐to‐propionate ratio decreased with the HC diet, but increased with 2MB supplementation. Propionate molar proportion and ruminal NH ₃‐N content increased with the HC diet, but decreased with 2MB supplementation. Neutral detergent fibre degradability decreased with the HC diet, but increased with 2MB supplementation. Crude protein degradability increased with the HC diet or 2MB supplementation. Abundance of Ruminococcus albus , Ruminococcus flavefaciens , Fibrobacter succinogenes and Bufyrivibrio fibrisolvens as well as activities of carboxymethyl cellulase, cellobiase, xylanase and pectinase decreased with the HC diet, but increased with 2MB supplementation. However, abundance of Prevotella ruminicola and Ruminobacter amylophilus as well as activities of α‐amylase and protease increased with the HC diet or 2MB supplementation. Total PD excretion also increased with the HC diet or 2MB supplementation. The results suggested that growth performance, ruminal fermentation, CP degradability and total PD excretion increased with increasing dietary concentrate level from 40% to 60% or 2MB supplementation. The observed diet × 2MB interaction indicated that supplementation of 2MB was more efficacious for improving growth performance, ruminal fermentation and total PD excretion with promoted ruminal bacteria abundance and enzyme activity in the MC diet than in the HC diet.     

杨属( Populus)黑杨组(Aigeiros)种(品种)间核型比较

 对杨属黑杨组(Aigeiros) 的15个种(品种) 核型进行了分析, 结果如下: 箭杆杨( Populusnigra var. thevestina) , 2n = 38 = 3M + 29m + 5 sm + 1 st; 盖杨( P. del.cv. ×Lux ×P.×canadensis cv. Shanhaiguanensis) , 2n = 38 = 2M + 27m + 4 sm + 5 st (4SAT) ; 欧美杨107 (P1 ×euram ericana cv. ‘74 /76’) , 2n = 38 = 1M + 29m (1SAT ) + 5 sm + 3 st (3SAT) ; 欧美杨13 ( P. ×euramericana CL 13) , 2n = 38 = 3M + 23m + 6 sm + 3 st (1SAT ) + 3 t (3SAT) ; 加杨( P. ×canadensis Moench) , 2n = 38 = 1M + 27m + 6 sm + 4 st ( 4SAT) ; 辽杨×美洲黑杨(P.maximowiczii Henry ×P.deltoids Bartr. ) , 2n = 38 = 1M + 24m + 9 sm (2SAT ) + 4 st; 中尚8号( P. ×Zhongshangnensis) , 2n = 38 = 4M + 27m (1SAT ) + 2 sm + 3 st (2SAT ) + 2 t; 北京杨( P. ×beijingensis) , 2n = 38 = 3M + 28m + 3 sm + 4 st (2SAT) ; 鲁山杨( P. ×Liaoningensis) , 2n = 38 = 1M + 27m + 3 sm + 6 st (1SAT ) + 1 t (1SAT) ; 廊坊1号( P. CL ‘Langfang 1’) , 2n = 38 = 3M + 28m + 3 sm + 4 st (2SAT) ; 圣山杨(盖杨类) (P. ×gaixianesis) , 2n = 38 = 2M + 27m + 4 sm (1SAT ) + 4 st (3SAT ) + 1 t; 抗- 2 〔P. deltoids CL 2 (GMO) 〕, 2n = 38 = 26m + 7 sm (2SAT ) + 4 st (1SAT ) + 1 t (1SAT) ; 群改3号( P. ×Qungainensis 3) , 2n = 38 = 1M + 27m + 8 st (2SAT ) + 2 t (2SAT) ; 中金2号( P. ×Zhongjinnensis 2) , 2n = 38 = 1M + 18m + 13 sm (1SAT ) + 5 st (2SAT) + 1 t (1SAT) ; 辽宁杨( P. ×eur. cv. San Martino ×P. ×canadensis cv. Shanhaiguanensis) , 2n = 38 = 2M + 26m + 6 sm + 4 st。黑杨各种(品种) 核型均为2B型, 种(品种) 间核型差异主要表现在中部着丝点(M、m) 染色体数目(25～32) 和端部着丝点( st、t) 染色体数目变化(1～6) 上, 核型特征为种(品种) 鉴定提供了一定参考。     

巴旦杏在甘肃河西地区引种培育问题的探讨

该文通过分析巴旦杏在甘肃河西地区引种培育过程中出现的问题,总结出用容器育苗和大田开沟点播相结合来培育接穗,以山桃为砧木嫁接巴旦杏的引种驯化技术.结果表明,容器培育接穗比直接大田点播出苗率、成活率分别提高了10%和15%;巴旦杏与山桃嫁接表现出极好的亲和性,嫁接成活率为90%.