野外放归大熊猫肠道菌群变化的研究

对四川卧龙中国保护大熊猫研究中心的一只野外放归亚成体大熊猫肠道菌群的组成和季节变化规律进行了研究,同时与其圈养双胞胎兄弟的肠道菌群进行了比较。从放归大熊猫粪便中分离出17种肠道菌,优势菌群为肠杆菌、肠球菌和乳杆菌。与圈养大熊猫相比,放归大熊猫肠道菌群中优势菌群的种类未发生改变,但是肠球菌数量增加,肠杆菌和乳杆菌的数量减少。研究发现放归大熊猫肠道菌群中的肠杆菌和肠球菌的数量随季节变化有较大波动,乳杆菌的数量随季节变化波动不大;而圈养大熊猫三种优势菌的数量随季节变化波动都不大。     

红三叶遗传图谱构建及抗白粉病基因QTL定位

本研究以感(岷山红三叶)、抗(澳大利亚红三叶品种♀Sensation×Renegade♂杂交新品系“甘农PR1”)白粉病红三叶材料为父母本杂交并种植成苗经人工接菌后筛选出抗、感白粉病的F₁群体为作图群体,利用AFLP标记构建红三叶高密度遗传图谱,并利用区间作图法对抗白粉病QTL进行了定位分析,可以为红三叶抗白粉病基因克隆和转基因等分子辅助育种奠定基础。结果表明,149个AFLP标记构建得到的遗传图谱包含7个连锁群(LG1,LG2,LG3,LG4,LG5,LG6和LG7),遗传图谱的总距离为640.5 cM。其中,LG1连锁群的遗传距离(140.6 cM)和标记间平均距离(9.4 cM)均最大;LG4连锁群的遗传距离(55.2 cM)和标记间平均距离(1.8 cM)最小。应用区间作图法对红三叶抗白粉病基因进行QTL分析定位,共检测到5个抗白粉病相关QTL位点(qrp-1,qrp-2,qrp-3,qrp-4和qrp-5),其中qrp-1、qrp-2、qrp-3和qrp-4位于LG4连锁群上,qrp-5位于LG5连锁群上。5个QTL位点对抗白粉病的贡献率为29%~90%,qrp-1对红三叶白粉病抗性的贡献率最大(90%),为主效QTL。     

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.     

河南春水镇农户对农业保险的认知情况分析

通过对河南春水镇农业保险的调查背景描述以及对河南春水镇农户进行走访和问卷调查的基础上,分析农户对农业保险的认知度及参与意愿,研究河南春水镇农户对农业保险的认知度以及其参加农业保险的意愿,并得出调查研究结论,最终提出应加大农业保险的宣传、转变农户思想观念以及增加农户农业收入的对策与建议.     

Identification of organic acid-related genes and their expression profiles in two pear (Pyrus pyrifolia) cultivars with difference in predominant acid type at fruit ripening stage

‘Yandangxueli’ is a pear cultivar with predominant citric acid in the ripe fruit, different from most of pear cultivars such as ‘Gengtouqing’ in which malic acid is the predominant acid type. It was found that ‘Yandangxueli’ accumulated citric acid for three times against that in ‘Gengtouqing’ at fruit ripening stage. To investigate the mechanism of citric acid accumulation in ‘Yandangxueli’, organic acids content, gene expression and enzyme activity were studied in both cultivars. Five genes, Pp:mtCs, Pp:cyAco, Pp:cyIdh, Pp:mtMdh and Pp:cyMe which encoded citric synthase (CS), cytosolic aconitase (cyACO), NADP-dependent isocitrate dehydrogenase (NADP-IDH), NAD-dependent malate dehydrogenase (NAD-MDH) and NADP-dependent malic enzyme (NADP-ME) respectively, were identified from pear fruit. Their expression profiles and the corresponding enzyme activities were determined throughout fruit development in both cultivars. Results from these enzymes indicated that there were no strict relationship between gene expression, enzyme activity and citric acid accumulation. Expression analysis for two Py:vVAtp genes encoding vacuolar H⁺-ATPase A subunit and one Py:vVpp gene encoding Vacuolar H⁺-pyrophosphatase showed that they were all with up-regulated expression at the later development stage of ‘Yandangxueli’ but with down-regulated expression in ‘Gengtouqing’. Therefore, it is concluded that the different ability in citric acid transportation and storage might be involved in the high citric acid content in ‘Yandangxueli’.     

花生抗黄曲霉相关基因PnLOX2的原核表达及RNAi载体的构建与转化

本研究对利用基因芯片技术从抗、感黄曲霉花生品种中分离出的差异表达基因PnLOX2进行原核表达,得到分子量为121.5 kD的融合表达产物;构建了PnLOX2基因的3'端反向重复结构并转化花生,得到了转基因花生苗,为反向鉴定PnLOX2基因在花生抗黄曲霉侵染过程中的功能奠定基础。     

青花菜锌指蛋白基因BoCCCH1的克隆和表达分析

CCCH锌指蛋白广泛存在于真核生物中,在植物的生长、发育和逆境胁迫响应中起着重要作用。为获知青花菜CCCH转录因子基因的序列特征和表达特性,从青花菜叶片中克隆到1个CCCH基因,命名为Bo CCCH1,同时,利用RT-PCR方法研究了其在不同器官及霜霉菌侵染叶片中的表达模式。序列分析结果表明,Bo CCCH1的基因组全长为1 568 bp,包含1个长度为599 bp的内含子,2个长度分别为627 bp、342 bp的外显子,编码322个氨基酸,蛋白质的分子量与等电点分别为35 296.42 Da和8.47;Bo CCCH1有2个锌指结构,类型均为C-X8-C-X5-C-X3-H。系统发育分析结果表明,Bo CCCH1与其它植物的21条同源序列在进化树上分为6组,来自十字花科的CCCH与Bo CCCH1处于同一分支。基因表达结果表明,Bo CCCH1在叶、花茎、嫩角果、花蕾和花中表达,其中花茎和嫩角果的表达量最高,但在根中未检测到表达;在霜霉菌侵染下,叶片Bo CCCH1的表达量升高,到24 h和36 h时达到最大,推测Bo CCCH1与霜霉病抗性相关。本研究为进一步探明Bo CCCH1在霜霉病抗性反应中的功能奠定了基础。     

云南小麦品种（系）锈病和赤霉病抗性功能基因的KASP标记检测

利用5个锈病成株期抗性基因的KASP标记Sr2_ger9 3p、Lr34jagger、CSTM4_67G、Lr68-2、VPM_SNP和抗赤霉病基因Fhb1的KASP标记TaHRC-KASP,对云南省育成的42个小麦品种（系）进行检测,旨在筛选出含有目标基因的优异小麦种质,为云南省持久抗病小麦新品种（系）的选育提供材料。结果表明,4个材料含兼抗型成株抗锈病基因Lr34/Yr18/Sr57,频率为9.52%;6个品种（系）含兼抗型成株抗锈病基因Lr67/Yr46/Sr55,频率为14.29%;7个材料含抗慢叶锈病基因Lr68,频率为16.67%;含兼抗型成株抗锈病基因Sr2/Yr30和成株抗叶锈基因Lr37的材料各有1个,频率均为2.38%;未检测出含抗赤霉病基因Fhb1的品种（系）。云麦69、云麦75、云麦56、宜麦1号和宜麦3号等兼有2个成株期抗锈病基因,可作为今后云南持久抗锈病育种的抗源材料。     

Lipid-rich bovine serum albumin improves the viability and hatching ability of porcine blastocysts produced in vitro

The effects of lipid-rich bovine serum albumin (LR-BSA) on the development of porcine blastocysts produced in vitro were examined. Addition of 0.5 to 5 mg/ml LR-BSA to porcine blastocyst medium (PBM) from Day 5 (Day 0 = in vitro fertilization) significantly increased the hatching rates of blastocysts on Day 7 and the total cell numbers in Day-7 blastocysts. When Day-5 blastocysts were cultured with PBM alone, PBM containing LR-BSA, recombinant human serum albumin or fatty acid-free BSA, addition of LR-BSA significantly enhanced hatching rates and the cell number in blastocysts that survived compared with other treatments. The diameter, ATP content and numbers of both inner cell mass and total cells in Day-6 and Day-7 blastocysts cultured with PBM containing LR-BSA were significantly higher than in blastocysts cultured with PBM alone, whereas LR-BSA had no effect on mitochondrial membrane potential. The mRNA levels of enzymes involved in fatty acid metabolism and β-oxidation (ACSL1, ACSL3, CPT1, CPT2 and KAT) in Day-7 blastocysts were significantly upregulated by the addition of LR-BSA. The results indicated that LR-BSA enhanced hatching ability and quality of porcine blastocysts produced in vitro, as determined by ATP content, blastocyst diameter and expression levels of the specific genes, suggesting that the stimulatory effects of LR-BSA arise from lipids bound to albumin.     

低温胁迫下马铃薯的数字基因表达谱分析

以马铃薯品种合作88为材料,利用数字基因表达谱(DGE)技术,对–2℃低温胁迫处理后的马铃薯叶片c DNA文库进行差异基因表达谱分析。结果表明,有28 505个基因受低温胁迫诱导差异表达,其中上调表达基因13 703个,下调表达基因14 802个。GO功能显著性富集分析表明,DEGs主要涉及信号生物代谢过程、氧化还原过程、能量代谢、次生代谢过程以及催化活性。KEGG富集分析表明,上调表达基因主要富集于苯丙烷、光合作用天线蛋白、类胡萝卜素的生物合成、苯丙氨酸代谢及淀粉与蔗糖代谢途径,而下调表达基因主要富集于植物激素信号转导途径。利用实时荧光定量PCR(q RT-PCR)验证4个DEGs在低温胁迫条件下的差异表达,其结果与DGE分析结果基本一致,证实了DGE测序结果的可靠性。