杜泊绵羊与小尾寒羊杂种优势利用研究

选杜寒F1、杜寒F2、杜寒F3、杜泊羊以及小尾寒羊（公母羔）并随机分组,研究探讨相同饲养条件对不同杂交种群生长发育和繁殖力的影响。结果表明：杜寒F1初生重公母羔平均为3．91kg,略低于父本杜泊羊（P〉0．05）;初生至断奶平均日增重318g,高于母本小尾寒羊（P〈0．01）。育肥期杜寒F1、杜寒F2和杜寒F3平均日增重分别比小尾寒羊提高40．99％、26．13％和22．52％（P〈0．01）;3个杂交代次间增重接近,依次是杜寒F1〉杜寒F2〉杜寒F3。杜寒F1母羊产羔率比杜泊羊提高40个百分点（P〈0．01）;多胎基因（FecB）检测结果和实际产羔情况基本一致（杜寒F1〉杜寒F2〉杜寒F3）。杜寒1～3代经产母羊体重、体高、体长、胸围指标均高于杜泊羊（P〉0．05）。杜寒F3体型外貌优于杜寒F2和杜寒F1,建议杜寒F1用于生产肥羔;可进一步探讨用带多胎基因的杜寒F3作父本,与杜寒F2实施横交,培育杜寒肉羊新品系。     

播种期对不同品种鸡冠花观赏性及结实性的影响

探讨了播种期对头状鸡冠花和羽状鸡冠花观赏性及结实性的影响。试验结果表明:播种期对两个品种鸡冠花的生育期有显著影响,头状鸡冠花观赏的最佳播期为5月31日左右,采种的最佳播期为6月30日左右;羽状鸡冠花观赏和采种的最佳播期均为6月15日左右。     

节瓜蓟马两性生殖与孤雌生殖研究

本研究证实了节瓜蓟马Thrips palmi孤雌生殖属于产雄性孤雌生殖(arrhenotoky)。在恒温(25±0.5℃)下,节瓜蓟马成虫两种生殖方式的产卵力比较结果表明,两种生殖方式下的成虫产卵力没有显著差异。两性生殖与孤雌生殖下成虫平均产卵量分别为55.69粒和54.90粒,平均日产卵量分别为2.455粒/d和2.275粒/d,平均寿命分别是22.67d和23.96d;产卵前期则均为2.25d。雄性个体平均寿命为19.33d,它与雌性个体平均寿命差异亦不显著。     

3个品系黄鳝的繁殖力比较研究

对黄斑鳝、青黄斑鳝、青斑鳝等3个品系的黄鳝进行繁殖力的比较研究.结果表明:体长192.0～567.0mm、体重23.2～491.5 g的黄斑鳝、青黄斑鳝和青斑鳝的个体绝对繁殖力(怀卵量)分别为1 072.7、957.7、834.1粒,相对繁殖力FL(绝对繁殖力/体长)分别为3.33、2.93、2.60粒/mm,相对繁殖力FW(绝对繁殖力/体重)分别为14.46、13.04、11.32粒/g.在黄鳝繁殖前1月内,黄斑鳝成熟系数超过15.0%的个体约占50%,而青斑鳝中约占35%,青黄斑鳝中不到12%.从绝对繁殖力、相对繁殖力以及成熟系数来看,黄斑鳝的繁殖力最强,青黄斑鳝次之,青斑鳝最弱.     

Effects of jasmonic acid-induced resistance in rice on the plant brownhopper, Nilaparvata lugens Stål (Homoptera: Delphacidae)

It has been established that jasmonate and its pure derivative, Jasmonic Acid can induce the emission of volatiles similar to those induced by herbivory which fed on the plant. Although the effects of induced resistance on chewing insects have been extensively studied, relatively little is known about their potential effects on phloem-feeding insects such as brown planthoppers. We studied the pattern of within-plant preference in the brown planthopper, Nilaparvata lugens (Stål) (BPH) (Homoptera: Delphacidae) and its consequences for offspring performance on the host-plant Oryza sativa L. (Taebaegbyeo variety) regarding the role of induced resistance of rice plants to hopper feeding. The present study examined the effects of induced resistance on the feeding (food assimilation and digestion), development, egg hatchability and survival. In this study, induced resistance was activated in rice using a foliar application of synthetic jasmonic acid (JA) (low 2.5 mM and high 5 mM). Induced resistance significantly reduced the longevity and egg hatchability of the adult N. lugens, as well as the percentage of nymphs surviving to maturity (only at high dose). This study also observed N. lugens food utilization, in order to evaluate the potential influence of induced resistance on N. lugens feeding behavior. The quantity of food ingested and assimilated by N. lugens on JA treated rice plants was significantly affected at the high dose of JA. These results indicate that JA application induces systemic defenses in rice that have a direct negative impact on N. lugens survivorship. At high concentration (5 mM) several abnormalities possibly related to defective moulting, were observed along with malformed eggs. These findings expand our knowledge the effects of JA-dependent defenses on phloem-feeding insects.     

温度对3种蚜虫生长发育及繁殖的影响

在不同温度条件下,对豆蚜、豌豆蚜、豌豆修尾蚜3种蚜虫发育历期、产仔量、寿命的影响进行了比较试验,结果显示,豆蚜发育起点为(6.05±1.44)℃,有效积温为(106.63±9.19)日度;豌豆蚜发育起点为(5.69±1.72)℃,有效积温(113.01±2.98)日度;豌豆修尾蚜发育起点为(4.02±2.22)℃,有效积温为(131.45±29.84)日度,3种蚜虫最适发育温度为19~23℃,在19℃时产仔量最多,其中以豌豆蚜的繁殖能力最强,达69.5头。     

Commercial honey bees (Apis mellifera) reduce the fecundity of an Australian native bee (Hylaeus alcyoneus)

European honey bees used for commercial honey production represent a potential source of competition for floral resources with native nectar and pollen feeding insects. This study reports the results of an experiment run over two years on the impact of commercial honey bees on the fecundity of a solitary native bee, Hylaeus alcyoneus. Registered apiary sites were used as treatment sites (with honey bees) while control sites (without honey bees) were interspersed between. The fecundity of H. alcyoneus was measured using trap nests. We compared the number of nests produced, number of eggs per nest and emerging progeny mass of H. alcyoneus in sites with and without commercial bee hives. The number of nests produced by H. alcyoneus was 23% less (Wilcoxon’s T) at treatment sites than control sites. Analysis of individual measurement intervals using ANOVA was compromised by a general lack of power. This result highlights that even though honey bees have been present in certain areas for many years, competition with native bees may still be occurring.     

Dynamics ofBetula ermanni population in subalpine vegetation in Changbai Mountain, Northeast China

Betula ermanni population was divided into three groups: the upper population (2 000–2 200 m), the middle population (1 700–2 000 m), and the down population (1 400–1 700 m) in Changbai Mountain. The dynamics ofBetula ermanni populations in subalpine vegetation are studied and the population life table, fecundity schedule, survival curves, age structure, and fecundity curves were established. The results showed that the, middle population is obviously, the transition from the upper population to the down population. This project is supported by Chinese Academy of Science Responsible editor     

温度对牛蒡长管蚜生长发育及繁殖的影响

在室内研究了温度对牛蒡长管蚜生长发育及繁殖的影响.结果表明:在10～30℃范围内,牛蒡长管蚜的发育速率随着温度的升高而加快;当温度超过34℃时,发育速率减慢.1龄、2龄、3龄、有翅型4龄、无翅型4龄、有翅型生殖前期、无翅型生殖前期、有翅型全若虫期及无翅型垒若虫期的发育起点温度分别为1.2376、1.2241、1.0238、3.0336、3.4524、3.9369、1.8460、1.7019和1.6249℃,有效积温分别为34.2194、37.3035、39.4693、44.2268、37.9152、14.3682、18.0239、187.3757和181.1123日·度.牛蒡长管蚜繁殖的最适温度在26℃左右.     

First results on spawning, larval rearing and growth of the wedge sole (Dicologoglossa cuneata) in captivity, a candidate species for aquaculture

The wedge sole is a target species in the fisheries of the Gulf of Cadiz (Spain). Having reared them to commercial size, we have studied reproduction and breeding in captivity of the wedge sole in this work here. The breeders adapt easily to captivity, and they can spawn in less than 1 year in captivity. The relative fecundity is relatively high, 1.06–2.33 · 10⁶ eggs kg⁻¹ per spawning season (mean 1.6 ± 0.1). Larval SGR is high, 7.2 ± 0.2% day⁻¹ (range 5.8–9.1), similar to other cultured flatfish species. In 1 year, some individuals reach market size and can release eggs, registering SGRs of 1.39–1.66% day⁻¹ (mean 1.56 ± 0.01). This species presents some very different characteristics with respect to other farmed flatfishes (turbot, halibut and Senegal sole, mainly), so that it is necessary to develop new techniques to optimise its cultivation. In the present work, the first results are presented on the biology of the wedge sole in captivity.