Reproductive biology of the female Japanese mantis shrimp Oratosquilla oratoria (Stomatopoda) in relation to changes in the seasonal pattern of larval occurrence in Tokyo Bay, Japan

ABSTRACT:   The reproductive traits and the monthly larval abundance of the mantis shrimp Oratosquilla oratoria were investigated in Tokyo Bay, Japan, in 2002. The goal of the study was to elucidate the cause of changes in the monthly pattern of larval abundance from the 1980s to the 1990s as these changes relate to variation in the stock size of the adult shrimp. Oogenesis was divided into 10 stages by histological observation. The developmental stage of oocytes in an individual's ovary was synchronous, suggesting that almost all the oocytes in an ovary are spawned at the same time. The size at first maturity was estimated to be 7 ≤ body length ( BL ) < 8 cm. Fecundity was expressed as a function of BL , ranging from 19 300 eggs for 8 cm BL to 92 100 eggs for 14 cm BL . Small female shrimps (<10 cm BL ) spawned around August. Most large female shrimps (≥10 cm BL ) spawned around May, and some large female shrimps also spawned until September. Although most large female shrimps spawned in spring, the larval abundance was low before July and high from August onwards. The results suggest that a substantial decrease in the stock size of large individuals causes the low larval abundance before July.     

病原菌诱导后黄瓜叶片中脂氧合酶活性与茉莉酸积累的关系

通过酶活性测定和高效液相色谱分析,研究经病原菌诱导后黄瓜叶片中脂氧合酶(LOX)活性与茉莉酸(JA)积累量的关系。结果表明,黄瓜经褐斑菌诱导后,叶片中茉莉酸(JA)大量积累,同时脂氧合酶(LOX)活性上升,接种叶片的上位叶中LOX活性和JA含量于诱导接种褐斑菌12h后开始升高,并于诱导接种24h后达到峰值,接种叶片的下位叶中LOX活性和JA含量在诱导接种12h后变化不大,但在24h后显著升高,并于48h达到峰值,此后逐渐平稳下降。相关分析表明,LOX与JA呈显著正相关,相关系数r为0.92。同时通过喷施脂氧合酶抑制剂(NDGA)和添加茉莉酸的试验证实LOX是JA合成的关键酶。     

葡萄内生细菌的激活及其对霜霉病菌的抑制作用

为了探究化学诱导剂诱导葡萄抗霜霉病的特性与葡萄内生菌激活的关系,筛选出对葡萄霜霉病有较高生防效果的菌株,本研究通过光学显微镜、扫描电子显微镜观察和传统培养法,检测了葡萄茎段的内生菌,并应用4种化学诱导剂对葡萄叶片和茎段进行处理,对被激活的内生菌进行分离和生防效果的测定.结果显示,在光学显微镜和扫描电子显微镜下均可观察到...     

黄海北部辽宁近岸海域鳀产卵场分布特征及其影响因素

为掌握黄海北部辽宁近岸海域鳀(Engraulis japonicus)产卵场的分布特征及其关键环境因子,基于2021年4—12月开展的产卵场综合调查获取的鳀样品及其鱼卵密度数据,运用Garrison重心分布法阐释鳀产卵洄游分布特征及其主产卵期;通过基于Tweedie分布的广义可加模型(generalized additive model, GAM)的构建,分析主产卵期内鳀卵密度与同步获取的海水表层温度(SST)、海水表层盐度(SSS)、海水表层叶绿素浓度(Chla)、浮游动物丰度(Fd)、浮游植物丰度(Fz)和深度(Depth)等6个环境因子,以及时间(月份,Month)和空间(经纬度、Lon和Lat)因子之间关系,并识别主控因子。结果显示,海域内鳀产卵期较长,由4月持续至11月,5—8月为主产卵期,其中,5—6月为产卵盛期。鳀产卵场规模和位置时空变化明显,时空因子与鳀卵密度分布呈密切非线性相关(累积偏差解释率为48.1%),(SST, SSS) (18.7%)和Depth (5%)次之。鳀产卵期适温范围较广,产卵场分布表现出高温高盐(低温低盐)增效作用和高温低盐限制作用。产卵初期(4月),鳀产卵场规模和鱼卵密度均较低,产卵重心位于海洋岛东南侧深水区;盛期(5月底—6月初)在SST主导下,鳀产卵场规模和鱼卵密度均至年内最高值,核心产卵场位于石城岛–庄河河口一带海域;此后,随着辽南沿岸水系盐度的下降,高温低盐的抑制作用使SSS因素主导产卵鱼群避开沿岸海域,鳀产卵场迁移至外海深水区,7月后位于30~50 m等深线之间;9—10月鳀繁殖活动基本结束,10月鳀卵仅零星分布于调查海域,直至12月未有鳀卵采获。研究可为黄海北部辽宁近岸海域鳀产卵场研究及鳀资源合理开发利用提供参考依据。     

茉莉酸甲酯和磷酸氢二钾诱导柱花草对炭疽病的抗性

探究茉莉酸甲酯（Methyl Jasmonate,MeJA）和磷酸氢二钾（K2HPO4）诱导柱花草对炭疽病的抵抗作用。结果表明,二者浓度分别为0.001~0.1 mgmL-1和10~50 mmolL-1时,病情指数均显著降低（P0.05）,最佳诱导浓度分别是0.001 mgmL-1和30 mmolL-1,诱导效果分别是64.84 %和54.40 %。0.001 mgmL-1 MeJA处理组的过氧化物酶（POD）及多酚氧化酶（PPO）活性在48 h达到最大值,显著高于对照组。30 mmolL-1 K2HPO4处理组的POD与PPO活性分别在48和24 h达到最大值,显著高于对照组。两种诱抗剂处理的POD和PPO活性在接种早期增加了柱花草对炭疽菌的侵染的抵御能力,进而提高植株的抗病性。30 mmolL-1 K2HPO4处理组的过氧化氢酶（CAT）活性在48~72 h内上升,显著高于对照组,而0.001 mgmL-1 MeJA处理组的CAT活性除72 h显著低于对照组,其他时间点与对照组相差不大。说明在诱导柱花草抗病性方面,两种诱导抗性剂处理的诱抗效果与POD、PPO和CAT的酶活性的诱导的时间及程度有关。     

南海区驯养条石鲷亲鱼的初次性成熟和产卵

2008年4月初在广东省饶平县对2006年5月人工孵化和培育的2龄条石鲷（ Oplegnathus fasciatus）成熟亲鱼进行激素诱导,研究和观察条石鲷亲鱼初次性成熟的繁殖生物学。结果显示,在南海区全人工养殖的条石鲷亲鱼初次性成熟年龄为2龄,成熟亲鱼的最小型为全长245 mm、体质量610 g,最大个体为全长300 mm、体质量1450 g;产卵季节为4月10日~7月15日,产卵盛期为4月中旬至6月下旬;为升温产卵型鱼类,产卵温度为20.0~28.8℃,适宜的产卵温度为20.7~27.6℃;雌、雄亲鱼发育同步,个体大小和成熟年龄差别不大;雌鱼属于一年一次分批产卵类型,产卵期超过3个月;24尾初次性成熟雌性亲鱼的总产卵量为3180.0×104粒,日最高产卵量为341.5×104粒;其产卵量和受精卵质量与水温的变化关系密切,受精卵的浮卵率随温度的变化而变化,在水温相对衡定时,浮卵率相对稳定并维持在80%~95%的较高水平;受精卵平均卵径为（0.860±0.023）mm,油球径为（0.191±0.009）mm。     

Design and development of a geothermal temperature control system for broodstock management of channel catfish Ictalurus punctatus

A control system was designed to raise and maintain water temperatures within 0.03-ha earthen ponds to a range conducive for spawning (24–30 °C) channel catfish Ictalurus punctatus. Heating was done during February 2001 to April 2001, when temperatures would have otherwise prohibited spawning (<24 °C). Temperature was increased from 10 °C (ambient) by 2 °C per day, and maintained at 27 °C, by the addition of geothermally warmed water (36 °C). The control system substantially increased the controllability and precision of heating ponds compared to manual operation. Systems were designed to control sets of four ponds. In designing this control system, consideration of biological constraints was essential. Reproduction in channel catfish is most strongly influenced by temperature. Because cold fronts are common during the winter and early spring (January–March), it was essential to ensure that pond temperatures did not fall below the range for spawning. Constraints on the heating rate and temperature variability to maintain fish health and stimulate spawning behavior were considered. Components of the control system included temperature measurement devices (type-T thermocouples), a central electronic control unit, electronic switches and electrically actuated ball valves. In response to the temperature sensed by each thermocouple, the controller sent a message to close or open the valve. When the valve was opened, warm water was added to the pond to increase the average pond temperature. Hardware and algorithm design and initial system testing were the major components of this project. The final design incorporated information on relevant biological parameters and safety features including peak pond temperature, independent aeration and water pressure control mechanisms. Initial results indicate successful control of this biological system, and ongoing studies suggest similar mechanisms may be used for additional control objectives. In particular, this system could be used to vary pond temperatures to study biological responses and to cool ponds by addition of well water during summer months.     

水杨酸和水杨酸甲酯在植物抗虫中的作用及机制研究进展

本文综述了水杨酸(Salicylic acid,SA)、水杨酸甲酯(Methyl salicylate,MeSA)的生物合成途径、激活植物防御基因的表达而产生抗虫毒素或酶类、诱导植物释放互利素引诱天敌的研究进展,展望了SA和MeSA在虫害治理中的研究和应用前景。