淮河水系沙塘鳢形态生物学研究

测量分析了淮河水系沙塘鳢(Odontobutis obscura)的外部形态特征和框架特征,为其形态种质标准和系统分类研究提供参考。(1)可数性状:背鳍Ⅶ,Ⅰ-9~10,尾鳍14~15,臀鳍Ⅰ-7~8,腹鳍Ⅰ-5,胸鳍14~15,纵列鳞36~41,横列鳞14~18,体侧感觉乳突线鳞28~30,第一鳃弓鳃耙数9~11,脊椎骨数28~29。可量性状:全长是体长1.23±0.03倍,体长是体高3.82±0.45倍、是头长3.08±0.49倍、是尾柄长5.19±0.54倍、是消化道长1.86±0.52倍、是肠长6.99±2.86倍,头长是吻长的2.94±0.42倍、是眼径6.09±0.87倍、是眼间距3.86±0.61倍、是口裂宽1.94±0.27倍,体高是体厚的0.96±0.11倍,尾柄长是尾柄高1.66±0.18倍。(2)体重与体长相关式为W=0.0454L2.7989,r=0.9790。肥满度系数K=2.90±0.32。通过形态性状比较和取样水系分析,认为淮河水系沙塘鳢与中华沙塘鳢的亲缘关系值得进一步探讨。     

盐分胁迫对大麦种子萌发的影响

通过对八个大麦品种种子萌发期间进行NaCl 胁迫实验研究.结果表明,随着NaCl 胁迫浓度的增大,种子发芽率、发芽指数逐渐降低,相对盐害率增加,种子萌发受到的抑制作用明显增强;80 mmol/L 的NaCl 浓度是大麦种子萌发的阀值.不同大麦品种对NaCl 胁迫的敏感程度不同,供试品种中以盐90260和C2118为萌发期较为耐盐的大麦品种.其它品种对盐分胁迫相对敏感.     

近亲真宽水蚤的外部形态及附肢结构

对近亲真宽水蚤Euryternora affinis成体的外部形态和附肢结构等进行了观察.近亲真宽水蚤雌性体长为1.28～1.40 mm,雄性体长为1.13～1.23 mm.其主要特征是:雌性生殖节左右两侧的凸起对称,雌性第五胸肢的第四节末端刺毛左、右肢等长,第三节刺毛的外缘不具锯齿;雄性第五胸肢基节左侧不具突起,末端节也不具有长钩状突起.近亲真宽水蚤在室内单用单胞藻可以培养成活,而在室外培育中,近亲真宽水蚤常可捕食轮虫.根据对其口部附肢的解剖观察,可知这种桡足类的食性为混合型(杂食性).近亲真宽水蚤与本属的太平洋真宽水蚤Eurytemora Pacific有着较明显的区别.     

猪的垂体特异性转录因子基因多态性研究

研究采用PCR和DNA测序方法,对小型猪种(香猪、巴马猪)及对照猪种(上海白猪、大约克夏猪)的垂体特异性转录因子(PIT-1)基因1293位至2230位进行了单核苷酸多态性(SNP)分析。结果显示:在第5内含子中有多处发生突变,其中在1429位,香猪、巴马猪的所有个体均发生了G→A突变,而上海白猪、大约克夏猪则未发生突变;在第6外显子中未见任何突变。结论:PIT-1基因1429位可作为小型猪基因标记的候选位点。     

沪产哈密瓜采后贮藏温度对品质的影响

以沪产"雪里红"哈密瓜为试材,分别在3℃、5℃、7℃、10℃和常温条件下研究哈密瓜采后贮藏期间果实品质的变化。结果表明:采用低温贮藏能有效降低哈密瓜果实失重,并抑制总酸、总糖和可溶性固形物含量的下降。3℃贮藏温度明显延缓了"雪里红"品质的下降,保持较高的感官和营养品质,贮藏保鲜效果最佳。     

不同果袋套袋对幸水梨品质的影响

选用了12种不同类型果袋对幸水梨进行套袋比较试验,结果表明:套袋后幸水梨果实的硬度、可滴定酸含量比对照显著增大;可溶性固形物、可溶性总糖含量以及单果重均显著降低,分别比对照平均降低8.47%,10.59%,20.85%;对还原型Vc含量影响显著,套袋果还原型Vc含量比对照增加10%-39.9%;套袋对果实光洁度和果点等外观品质明显改善。综合研究认为双层袋L2-1为幸水梨果实套袋处理的最佳选择。     

美国食用菌产业发展报告

通过利用美国农业部、农业统计局及相关行业网站发布的产业数据、新闻报道和研究报告,对美国食用菌产业的变化趋势及其原因进行梳理.结果发现,随着生产效率的提高美国食用菌产量和产值逐年提高,但通过不断的兼并收购,食用菌生产者的数量明显下降.在政府组织和行业自发的行业组织和协调下,美国食用菌行业竞争有序,食用菌价格稳定,食用菌产...     

植物源杀虫剂及其木醋液混合液对油松毛虫的防治效果

研究了白屈菜、大活的超声波水提物及其木醋液混合物对油松毛虫的防治效果。结果表明:白屈菜提取物加木醋液配制的杀虫剂稀释100倍,防治油松毛虫效果较好,死亡率为53.33%;大活提取物加木醋液配制的杀虫剂稀释5倍,防治油松毛虫效果最好,死亡率达到86.67%。     

赖氨酸硫酸盐相对于赖氨酸盐酸盐的生物学效价评定

本文旨在通过对肉仔鸡生长性能、氮平衡和血浆尿素氮指标来比较赖氨酸硫酸盐相对于赖氨酸盐酸盐的生物学效价,以便为赖氨酸硫酸盐在肉鸡中的合理应用提供科学的理论依据。选用486只1日龄爱拔益加肉公鸡评定赖氨酸硫酸盐相对于赖氨酸盐酸盐的生物学效价。鸡只预饲3d,第4天按体重随机分为9个处理,每个处理9个重复,每个重复6只鸡。分别通过赖氨酸硫酸盐或赖氨酸盐酸盐向玉米-玉米蛋白粉-花生粕-麦麸型基础日粮中添加0.09%、0.18%、0.27%和0.36%的赖氨酸。结果表明,4～21d赖氨酸硫酸盐相对赖氨酸盐酸盐的效价分别为:0.93(日增重)、0.86(饲料转化效率)和0.95(氮存留);22～42d赖氨酸硫酸盐相对赖氨酸盐酸盐的效价分别为:1.01(日增重)、1.36(饲料转化效率)和1.06(氮存留);对于生长全期,赖氨酸硫酸盐相对于赖氨酸盐酸盐的生物学效价分别为:0.99(日增重)、1.07(饲料转化效率)和1.03(血浆尿素氮)。可见,由不同指标得到的赖氨酸硫酸盐相对赖氨酸盐酸盐的生物学效价不同,但总的平均相对效价为1.03。即两者对肉鸡的生物学效价相当。     

Isolation and Characterization of GhLEA3 Gene from Upland Cotton and Its Expression in Response to Low Temperature Stress

[Objective] Based on the analysis of cotton GhLEA3 gene structure and its expression model in chilling stress, we investigated the resistance function of GhLEA3 in response to cold stress. [Method] We cloned GhLEA3 from upland cotton by homologous sequence cloning way. We analyzed the properties of the GhLEA3, and constructed phylogenetic tree by bioinformatics analysis. We constructed the transient expression vector 35S∷GhLEA3-GFP by In-Fusion connection technology and studied the subcellular localization of GhLEA3. The expression of GhLEA3 gene in leaves of TM-1 at three-leaf stage under low temperature stress treatments (4 ℃, 24 h) was performed. Agrobacterium tumefaciens mediated floral dipping method was used to transform the gene with expression vector 35S∷GhLEA3-GFP into Arabidopsis thaliana wild type. Low temperature germination experiment at 4 ℃ was conducted to verify germination ability of the transgenic Arabidopsis thaliana T₃ seed. The transgenic Arabidopsis seedlings were treated at 4 ℃(low temperature), and all the leaves were taken to measure their electrical conductivity. [Result] The coding sequence of GhLEA3 gene is 1 218 bp, which encodes 405 amino acids. GhLEA3 protein includes 4 functional domains of PF02987. Phylogenetic analysis showed that the similarity of amino acid sequences between upland cotton GhLEA3 and Arabidopsis thaliana AtLEA3 was 52.6%. GhLEA3 might be mainly localized in vacuoles and small vesicles. GhLEA3 was up-regulated in leaves after low temperature treatment. The germination rate of transgenic Arabidopsis thaliana of T₃ generation at low temperature was significantly higher than that of wild type, and its electrical conductivity of leaves after low temperature treatment was significantly lower than that of wild type. [Conclusion] GhLEA3 belonged to the member of LEA3 family. Phylogenetic analysis showed that GhLEA3 had the closest relationship with AtLEA3. GhLEA3 was induced by low temperature stress and may play an important role in improving cold resistance.