不同性诱剂对亚洲玉米螟的引诱效果及田间应用初探

亚洲玉米螟Ostrinia furnacalis(Guenée)是危害我国玉米的重要害虫,为了探索其生物防治方法,测试了不同来源的3种诱芯(诱芯A、诱芯B和诱芯C)对陕西关中灌区玉米螟的引诱活性,并比较了水盆式和三角形两种诱捕器类型及诱捕器不同悬挂高度(1.0、1.5、1.8和2.0 m)的诱捕效果。结果表明:诱芯A(北京中捷玉米螟诱芯)和诱芯B(中国科学院动物研究所玉米螟诱芯)均对亚洲玉米螟成虫具有一定的引诱活性,以诱芯B效果更佳;两种类型诱捕器对玉米螟诱虫总数差异显著;三角形诱捕器悬挂在2.0 m处的效果优于悬挂在1.5 m处。诱芯B较适合陕西关中灌区玉米螟的预测预报及生物防控,建议在田间应用中使用三角形诱捕器,悬挂高度以1.8~2.0 m为宜。     

二化螟性诱剂田间应用技术研究

探讨二化螟性诱剂田间应用中的相关技术问题,为二化螟性信息素的科学合理应用提供依据。采用2种市售二化螟诱芯,比较了诱捕器的类型、颜色及悬挂高度对二化螟诱捕效果的影响。结果表明中科院动物所二化螟诱芯B引诱效果较好,粘胶板式（三角板）和水盆式2种类型诱捕器的引诱活性无显著差异;诱捕器颜色对引诱效果有较大影响,其中白色效果优于绿色、蓝色、黄色、黑色、红色、棕色;三角板诱捕器悬挂在1.4m和1.2m处的效果优于1.0m和0.8m。田间应用时建议选用中科院动物所二化螟诱芯B,采用白色三角板诱捕器,悬挂高度以1.2~1.4m为宜。     

不同日龄池塘养殖中华鳖形态性状对体重的影响

为分析不同日龄池塘养殖雌雄中华鳖体重与形态性状的相关性,随机选取100及300日龄雌雄中华鳖各50只,采用相关分析、通径分析计算了背甲长、背甲宽、腹甲长、体高和体重的表型相关及不同性状对体重的影响程度。结果表明,雌雄中华鳖背甲长、腹甲长及体高有显著差异(P0.05)。各性状与体重之间的相关系数均达到显著水平(P0.05)。100日龄中华鳖,背甲长对雌鳖体重的直接影响最大,对体重的决定程度最高;腹甲长对雄鳖体重直接影响最大,对体重的决定程度最高。300日龄中华鳖,背甲长对雌雄个体体重直接影响最大,决定程度最高。     

DlSx-AF4S标记在柿及其杂交后代性别鉴定中的有效性研究

柿（Diospyros kaki Thunb.）优良品种一般仅开雌花且单性结实能力强,早期剔除雄性后代是提高育种效率的重要措施。在柿的近缘种君迁子（D. lotus L.）中已经筛选出一个与雄性性状紧密连锁的DlSx-AF4S标记,但其在包括栽培柿及其杂交后代性别鉴定中的有效性尚不完全明确。利用该标记对268份相关试材进行性别鉴定,并与其花性观察结果相比较。结果表明：（1）116份柿（D. kaki）种质中除‘罗田甜柿’、‘兴义水柿’、‘甘百目’、‘商城冬柿’外,其余112份试材的DlSx-AF4S标记鉴定结果与其田间性别表现一致,鉴别率96.6%;（2）11个柿（D. kaki）杂交组合共118份F1代中有51份进入成花状态,DlSx-AF4S标记检测与已知花性的46份试材一致,鉴别率90.2%;（3）DlSx-AF4S标记在‘华柿1号’ב罗田甜柿’F1代中呈现近1︰1分离;（4）DlSx-AF4S标记在柿和君迁子之外的其他供试柿属植物中也表现出良好的通用性。以上结果表明,DlSx-AF4S标记可用于柿及其杂交后代雄性性别的早期鉴定。     

陕西延川枣镰翅小卷蛾发生规律

为有效监测和防治枣镰翅小卷蛾,采用性诱剂诱捕的方法,观察了枣镰翅小卷蛾成虫的发生消长动态。结果表明,枣镰翅小卷蛾在陕西延川1年发生3~4代,其中以1年发生3代为主,个别的发生4代;越冬代成虫在3月中下旬开始羽化;有世代重叠现象;在枣树高度1.0~2.0m范围内,诱集到的成虫数量有一定差异,2.0m处分布最多,在运用性诱剂诱杀枣镰翅小卷蛾成虫时,应尽量将诱集器在枣树高度近2.0m处,以达到更好的诱捕效果;成虫活动时间主要在20:00-24:00及4:00-6:00时间段,其中在20:00-22:00及4:00-6:00时段活动更频繁、更活跃。     

通过CHD基因快速鉴定鸽子性别方法的研究

本试验采用PCR方法,依据性别基因连锁理论,通过羽毛和血液,不提取鸽子基因组DNA,直接利用特异性引物对其CHD基因的特异性片段进行扩增,琼脂糖凝胶电泳检测,结果显示雄鸽仅有1条带,在700bp左右,雌鸽有2条带,分别在400与700bp左右;利用该检测方法对100羽性别未知的雏鸽进行了性别鉴定,结果为雌鸽48羽、雄鸽52羽,并通过剖解雄鸽的生殖器官进行验证,准确率达到100%。用建立的方法测定了2928羽雏鸽用于蛋鸽留种试验,结果表明,雌鸽为1411羽、雄鸽为1517羽。     

伽马辐照对智利小植绥螨生殖及性别决定的影响

辐照可导致染色体变异,是研究生殖机理的常用辅助方法之一。本研究对不同生理状况下智利小植绥螨雌螨、雄螨、不同发育阶段卵进行不同剂量的伽马辐照,探索其后代发育与繁殖情况,以期解释智利小植绥螨性别决定机制及生殖机理。研究结果表明,在160~640 Gy辐照剂量下,辐照的未交配的雄成螨与正常的未交配的雌成螨交配,F1代中只有雄成螨且仅1/3可育。在45~90 Gy辐照剂量下,辐照的未交配的雌成螨与正常的未交配的雄成螨交配,其子代雌性比随着辐照剂量的增加而减小,且至90 Gy处理下无子代完成胚胎发育。辐照交配后产卵前的雌成螨,其子代雌性比间没有显著差异（77.5%~85.0%）。辐照卵龄0~12 h的卵,没有卵发育至成螨;辐照卵龄12~24 h的卵,其中发育至成螨的全为雌螨;辐照卵龄24~48 h的卵,其中发育至成螨的雌性比随着辐照剂量的增加具有增加的趋势。试验结果推测出父系染色体组参与形成配子且对性别起决定作用;父系染色体组异质化的时间可能集中于卵壳形成后至卵期12 h之间。本试验为智利小植绥螨父系染色体组参与性别决定的机制做出了新的诠释,对深入研究性别决定的机理具有重要的意义。     

Investigating factors contributing to reduced embryo survival in farm‐raised Atlantic salmon,Salmo salar L.

Embryo mortality of Atlantic salmon, Salmo salar, has been increasing for more than a decade in the State of Maine, a leading producer of this species in the United States. Increasing embryo mortality not only creates a financial bottleneck for farms but also prevents the sale of surplus eggs as an additional source of revenue. Blood and egg samples were collected at three Maine Atlantic salmon farms from female broodstock at the time of spawning over a 2‐year period. Correlative factors for reduced embryo survival were investigated by measuring egg and maternal plasma concentrations of 17β‐estradiol (E2), 11‐ketotestosterone (11‐KT), testosterone and calcium, as well as maternal hepatic ethoxyresorufin‐O‐deethylase (EROD) activity and fork length. Significant positive correlations were found between maternal plasma concentrations of E2 and 11‐KT and embryo survival. Interestingly, there was no correlation with egg concentrations of sex steroids and embryo survival, suggesting that embryo mortality does not likely rest with the maternal deposition of sex steroids into the egg, but with another hormone regulated process related to egg assembly, ovulation or post‐ovulatory ageing.     

Gonadogenesis in scallop Chlamys farreri and Cf‐foxl2 expression pattern during gonadal sex differentiation

Gonad development and sexual differentiation are important biological processes. More insight is needed in these processes to improve selection and breeding efficiency in the production of culture animals for monosex farm operations of commercially important shellfish species. Foxl2 is the earliest known sex dimorphic marker of ovarian differentiation in mammals, but studies on foxl2 in invertebrate species are rare. This study revealed the gonadogenesis and expression characteristics of foxl2 during the gonadal differentiation in the scallop Chlamys farreri, an important commercial mollusk in China. The result showed that C. farreri gonad becomes visible once juveniles reach a shell height of 5.5 mm. Sex can be distinguished based on gonad histology in animals with a minimum shell height of 9 mm. Expression of Cf‐foxl2 (C. farreri foxl2) was first observed in cytoplasm of ovarian germ and follicle cells, just after the initiation of ovarian differentiation. Results indicate that Cf‐foxl2 can be used as an early sex‐marker gene, and may have participated in the regulation of ovary differentiation in C. farreri.