桑叶提取物1-DNJ对小菜蛾幼虫生物活性的影响

为研究桑树叶片生物活性物质1-DNJ的杀虫作用机理,以小菜蛾(Plutella xylostella L.)为研究对象,利用桑树叶片提取物1-DNJ饲喂小菜蛾3龄幼虫,研究1-DNJ对小菜蛾拒食、触杀、胃毒和生长等生物活性的影响。结果表明,1-DNJ处理后,小菜蛾48 h和72 h的拒食率分别是93.33%和89.25%,拒食中浓度为0.34 g/L和0.58 g/L。同时,1-DNJ对小菜蛾幼虫的生长发育具有明显抑制,小菜蛾化蛹率随着1-DNJ浓度增加而显著下降,但对小菜蛾的蛹重作用不大。1-DNJ对小菜蛾的触杀和胃毒作用效果没有拒食和生长抑制的作用明显。结果说明,桑树叶片中的1-DNJ主要通过拒食作用影响小菜蛾生长,进而达到防控的目的。     

福建农林大学科研团队在全球首次破译世界性害虫小菜蛾基因组

<正>福建农林大学副校长尤民生教授带领的科研团队在全球首次破译世界性害虫小菜蛾基因组。此举奠定了中国在小菜蛾基因组研究领域的国际领先地位,并将为农业害虫的可持续控制提供新的研究思路。由尤民生教授主持、深圳华大基因研究院共同完成、英国剑桥大学等参与的小菜蛾基因组研究成果"小菜蛾杂合基因     

春甘蓝田小菜蛾种群动态研究

在田间系统调查的基础上,采用模糊聚类分析和时间动态空间生态位宽度与种群密度关系分析方法,研究了合肥地区春甘蓝田小菜蛾的种群动态,旨在为小菜蛾的科学治理提供依据。研究结果表明,春甘蓝田小菜蛾种群动态可分为3 个发展阶段——点片发生阶段（低密度、高聚块）、扩张发生阶段（中密度、低聚块）和猖獗发生阶段（高密度、低聚块）。小菜蛾对春甘蓝的为害情况比较复杂,种群密度较低时主要为害甘蓝心叶;随着甘蓝的生长和小菜蛾种群密度的上升逐渐向内层叶和外层叶扩展,最终导致甘蓝全株受害。小菜蛾种群处于点片发生阶段时是春甘蓝田小菜蛾防治的关键时期。     

温度对小菜蛾成虫繁殖和寿命的影响

为了对小菜蛾 (Plutella xylostella L.)发生为害的种群动态规律提供参考。研究了5种恒温对小菜蛾实验种群的存活,繁殖与寿命的影响。结果表明：在15、20、25、30、35℃的范围内,小菜蛾的产卵前期和历期随着温度的升高而缩短。在35℃高温下,37.5%的小菜蛾雌虫不孕,且正常雌虫的产卵量显著减少,仅为75.7粒/雌,说明持续高温对小菜蛾成虫的产卵是不利的。小菜蛾的繁殖动态也随着温度不同而不同,小菜蛾雌虫的卵峰日都在开始产卵的3日内,累积产卵量达总卵量80%的雌虫日龄随着温度的升高而缩短。小菜蛾雌虫的寿命也随着温度升高而明显缩短,两者呈显著性负相关(r=-0.981,P<0.05)。     

杀虫剂对不同蔬菜上小菜蛾毒力及种群动态的影响

通过毒力测定和田间调查,测定了甘蓝、小白菜上的小菜蛾幼虫对敌敌畏、高效氯氰菊酯、阿维菌素的药剂敏感性,以及阿维菌素作用下的不同蔬菜品种上的小菜蛾幼虫的种群动态。结果表明,不同年份、不同蔬菜品种上的小菜蛾对不同杀虫剂的药剂敏感性存在差异。2003年敌敌畏对甘蓝上小菜蛾LC50与2004年的之间没有差异,但2005年的LC50明显高于2003年,但在各调查的年份,小白菜上的小菜蛾对敌敌畏的药剂敏感性没有差异,从蔬菜品种来看,只有在2005年,敌敌畏对甘蓝上小菜蛾的LC50大于小白菜;在各个调查年份,高效氯氰菊酯对甘蓝上小菜蛾的药剂敏感性没有差异,只有2005年高效氯氰菊酯对小白菜上小菜蛾的LC50明显高于2003年,高效氯氰菊酯对甘蓝上小菜蛾的LC50与小白菜上的没有差异;2003年阿维菌素对甘蓝和小白菜上的小菜蛾LC50与2004年之间没有差异,但2005年的LC50明显高于2003年;在调查的各个年份,阿维菌素对甘蓝上小菜蛾的LC50与小白菜上的没有差异。施用阿维菌素对小菜蛾田间种群有明显抑制作用。施用1次阿维菌素的菜田中,虫量回升缓慢,最高值虫量仅约为对照菜田最高峰时的一半;施用阿维菌素2次的菜田中,虫量相对较低,仅在第2次药前有一个小高峰;在甘蓝和小白菜菜田中,小菜蛾幼虫种群数量动态基本一致,但甘蓝菜田的小菜蛾数量明显高于小白菜菜田     

几种杀虫剂对抗性小菜蛾的毒力分析及田间防治效果评价

摘 要：研究旨在明确几种常用杀虫剂对抗性小菜蛾种群的室内毒力和田间防治效果,以及小菜蛾抗性水平与杀虫剂防治效果之间的相关性。笔者测定了7种杀虫剂对田间抗性小菜蛾种群的室内毒力,并进行了7种杀虫剂在登记剂量下防治小菜蛾的田间药效试验。结果表明：7种杀虫剂对靶标小菜蛾种群的室内毒力大小依次为：多杀菌素、氯虫苯甲酰胺、阿维菌素、虫螨腈、茚虫威、丁醚脲、高效氯氰菊酯,其LC50值分别为1.14、1.81、2.27、4.22、4.59、45.80、156.96 mg/L。该小菜蛾种群对丁醚脲、茚虫威和多杀菌素的抗性倍数分别为2.14、8.83和9.50,处于低水平抗性;对虫螨腈、氯虫苯甲酰胺和高效氯氰菊酯的抗性倍数分别为10.55、30.17和44.21,处于中等水平抗性;对阿维菌素的抗性倍数达113.50,已达高水平抗性。多杀菌素、茚虫威、氯虫苯甲酰胺和丁醚脲对小菜蛾的田间防效相对较好,药后7天防效分别为89.38%、90.67%、84.10%和86.18%。田间小菜蛾种群对7种杀虫剂均产生不同程度抗性,杀虫剂登记剂量处理下对小菜蛾的田间防效与小菜蛾对该药剂的抗性水平存在较明显的负相关性。     

小菜蛾颗粒体病毒应用试验研究

为探索防治小菜蛾安全、经济、有效的防治方法。于1999—2001年进行了小菜蛾颗粒体病毒防治小菜蛾的应用试验研究。结果表明，小菜蛾40～60病死虫／667m^2。药效测定和田间防治效果达到80％～90％。与常用的50％甲胺磷1500倍效果相当，田间防治效果特别好。同时对小菜蛾颗粒体病毒的土法生产和适宜农户应用的简易保存方法进行研究试验．效果较好。     

拟环纹豹蛛和前凹豹蛛对小菜蛾的捕食作用

为了明确拟环纹豹蛛和前凹豹蛛对小菜蛾幼虫的捕食作用,通过研究不同温度下2种蜘蛛对小菜蛾幼虫捕食量和不同空间下拟环纹豹蛛对小菜蛾的捕食效应,利用三因子五水平二次通用回归旋转组合分析2种蜘蛛对小菜蛾幼虫的联合控制作用和拟环纹豹蛛对小菜蛾、斜纹夜蛾幼虫的控制作用。结果表明,2种蜘蛛对小菜蛾捕食量随温度增加出现先增加后降低。拟环纹豹蛛对小菜蛾的捕食作用大于前凹豹蛛,2种蜘蛛对小菜蛾四龄幼虫捕食功能反应符合Holling-Ⅱ型,但Holling-Ⅲ型能完善2种蜘蛛对小菜蛾幼虫的捕食作用评价。不同体积对拟环纹豹蛛的取食作用影响较大,瞬时攻击能力a′、处理1头猎物所用的时间T_h和捕食作用a′/T_h在小体积要高于大体积。2种蜘蛛对小菜蛾幼虫联合捕量与三者密度正相关,总体平均效应为：小菜蛾幼虫密度＞前凹豹蛛密度＞拟环纹豹蛛密度。小菜蛾和斜纹夜蛾密度能显著影响拟环纹豹蛛的取食量,但拟环纹豹蛛对小菜蛾幼虫和斜纹夜蛾幼虫没有偏嗜性。本研究可为评价这2种蜘蛛对田间小菜蛾的控制作用提供参考。     

半夏乙醇提取物对小菜蛾幼虫生物活性的研究

摘 要：【目的】为了有效控制小菜蛾的危害,研发新型、高效植物源杀虫剂。【方法】采用95%乙醇对半夏干粉进行索式提取,以叶片浸渍法和浸虫法测定了提取液对小菜蛾幼虫的杀虫活性。【结果】 半夏乙醇提取物对小菜蛾3龄幼虫具有较好的拒食、触杀、胃毒和生长抑制的作用,提取物浓度越高,效果越明显。在触杀试验中,当提取物在100 mg/ml浓度下,处理72h后小菜蛾幼虫的校正死亡率为61.44%。在选择性拒食试验中,提取物对3龄幼虫的AFC50分别为32.68 mg/ml（24h）和39.16 mg/ml (48h) ;在非选择性拒食试验中,提取物对3龄幼虫的AFC50分别为17.26 mg/ml（24h）和21.32 mg/ml (48h)。半夏乙醇提取物对小菜蛾的胃毒及生长发育抑制作用也明显。饲喂72 h时,浓度为100 mg/ml处理的小菜蛾幼虫校正死亡率高达69.41%;在处理48 h,浓度为100 mg/ml的提取物对小菜蛾3龄幼虫的生长抑制率为64.43%。【结论】半夏提取物对小菜蛾幼虫具有较高的生物活性和理想的控制效果。     

屯留县甘蓝小菜蛾发生规律和防治技术

<正>小菜蛾属菜蛾属鳞翅目菜蛾科,是甘蓝上的重要害虫。小菜蛾食性专一,以十字花科蔬菜为主,特别喜食甘蓝、大白菜,在屯留县属常发性和大发生性害虫。1发生规律为了摸清小菜蛾在屯留县的发生规律,2009年我们采用小菜蛾性诱剂进行成虫诱集,通过连续的诱蛾观测,确认小菜蛾在我们当地一年发生5~6代,并且世代交替重叠,幼虫周年均在十字花科蔬菜上发生和为害。     

Acquired Thermo‐Tolerance and Trans‐Generational Heat Stress Response at Flowering in Rice

In rice, pre‐exposure to sublethal treatment followed by harsh lethal treatment is known to improve tolerance of different abiotic stresses at the vegetative stage within and across generations. Our major aim was to test the phenomenon of thermo‐tolerance at flowering across (trans)‐generations and within generation using rice cultivars contrasting for heat stress tolerance at flowering. To test trans‐generational response, plants were exposed to higher temperature at flowering stage and seeds obtained from previous generations were exposed to heat stress during flowering, which recorded significantly lower fertility when exposed to the same degree of stress in their subsequent generations. A pre‐acclimation to moderately high acclimating temperatures imposed over three different durations during the vegetative and initial reproductive stage showed positive response in the tolerant N22, particularly under severe heat stress (40 °C). This finding indicates the possibility of acquiring ameliorative thermo‐tolerant mechanisms at anthesis, restricted to tolerant genetic backgrounds to combat subsequent harsh conditions within the same generation. However, trans‐generational memory was ineffective in mitigating spikelet sterility losses in both tolerant and susceptible backgrounds. Rice is extremely sensitive to heat stress during flowering; hence, similar exercise across other crops of interest needs to be carried out before generalizing conclusions.     

Use of somaclonal variation and in vitro selection for chilling tolerance improvement in rice

Embryo-derived calli of four rice varieties cultivated at high altitude in Burundi — Facagro 57, Facagro 76, Kirundo 3 and Kirundo 9 — were submitted to different temperature regimes. The percentage of regenerating calli greatly varied depending on variety, length of culture and callus temperature treatment. The reduction of regeneration percentages induced by low temperature was more pronounced in the more sensitive varieties. Regenerated plants (R0) and their progenies in R1, R2 and R3 were cold-screened together with control plants. In all varieties, significantly higher survival rates were obtained in R3 with in vitro plants than with control plants. Such chilling tolerance improvement was not obtained following a massal selection applied during 3 successive generations onto the control plants. In vitro plants regenerated from calli cultivated either at 25 °C, either at 4 °C, were cultivated at different altitudes in Burundi during two successive generations. For most observed traits, the in vitro plants were characterized by lower means, larger variation and higher maximum values than the control plants. The most chilling-tolerant somaclonal families were most usually characterized by extensive differences in fatty acid composition, chilling-induced electrolyte leakage and chlorophyll fluorescence, compared to the varieties they derived from. This revised version was published online in July 2006 with corrections to the Cover Date.     

高粱空间诱变效应研究

1996年利用我国第17颗返回式卫星对高粱唐恢28恢复系种子进行搭载处理后，对其变异后代进行了田间鉴定和同工酶及RAPD分析。主要结果如下：（1）SP1代获得一个特大穗型突变体（MTR28），其后代性状分离广泛，变异类型丰富，从中获得了遗传性状稳定且具有不同特点的高产、抗病优良变异选系；（2）优良变异选系组配的杂交种产量明显高于对照，可应用于生产上组配高产、抗病杂交种；（3）空间诱变后代性状稳定时间比常规杂交后代稳定快2—4个世代，可缩短育种进程；（4）变异选系在酯酶同工酶和细胞色素氧化酶同工酶酶带种类及酶活性上存在着较大的遗传差异；（5）RAPD分析结果显示，空间诱变选系在基因组水平上发生了明显的变化。     

Combining ability and correlations for yield components in early generations of potato breeding

A partial diallel set of crosses was made between 14 potato cultivars chosen for their fertility, from those included in a potato breeding programme at the NEIKER – Basque Institute for Agricultural Research. The progeny were grown in completely randomized trials from 1997 to 1999. Performance for yield, tuber number and average tuber weight was analysed in seedling and two clonal generations. Variance estimates due to both general combining ability (GCA) and specific combining ability (SCA) were significant in all generations for all traits under study. However, SCA was more important than GCA in almost all cases. Correlation coefficients among characters, generations, GCA and SCA effects were examined. For tuber yield no relation was obtained between generations; however, average tuber weight and yield were positively associated in all generations. The results indicate that appropriate selection criteria depend strongly on the particular cross. The implication for a breeding strategy are discussed.     

组织培养途径改良定型小麦品种的研究

选用ＣＡ９０７０、ＣＡＤ８６９４,京４１１三个定型品种进行组织培养,比较了三种培养方式的培养效果,调查了Ｈ２,Ｒ２株系主要农艺性状的遗传变异情况,结果表明,幼胚培养效率最高,基因型间差异小,花药培养的基因型间差异显著,花药培养后代农艺性状的变异率高于幼胚培养,且其性状值向更小的方向变异,而幼胚培育诱花的变异范围大于花药培养,获得了ＣＡＤ８６９４的花培变异株系９５Ｈ０５５,株高降低了１１．５ｃｍ,获     

Investigations into the causes of segregation of Ogura male sterility in Bangladeshi cultivars of radish

In a series of three experiments during 1998‐99 and 1999‐2000 at Gazipur, Bangladesh, the causes of segregation of Ogura cytoplasmic genetic male sterility in local cultivars of radish were studied. Male‐sterile populations at the BC₅ and BC₆ generations were grown under a range of field temperatures for 2 years and the results on pollen fertility tests revealed that the expression of male sterility was not affected by temperature. Neither was a genotype‐year interaction found. The unexpected segregation observed in the male‐sterile backcross generations might be due to the presence of restorer alleles in the maintainer parents.     

Genetic analysis of low-temperature tolerance during germination in tomato, Lycopersicon esculentum Mill.

The genetic basis of low-temperature tolerance during germination of tomato seed was investigated using two approaches. First, a cold-tolerant (PI 120256) and a cold-sensitive tomato cultivar (UCT5) and their reciprocal F₂, F₃ and BC₁ progeny (total of 10 generations) were evaluated for germination at a low (11 ± 0.5°C) and a high (control) temperature 20 ±0.5° C) Weighted least-square regression analysis indicated that in the low-temperature treatment most of the variation resulted from additive genetic effects, and dominance and epistatic interactions were nonsignificant. Partitioning of the total genetic variance into those attributable to the effects of embryo, endosperm, testa and the cytoplasm indicated that additive effects of endosperm and embryo could individually account for 80% and 77% of the total variance, respectively. In the control treatment, greater than 60% of the variation could be explained by individual additive effects of endosperm or embryo and ? 27% of the variation could be explained by embryo dominance effects. Across generations, there was a positive correlation (r = 0.78, P < 0.01) between germination in the control and low-temperature treatments and there were no significant genotype × temperature interactions. The results indicate the presence of similar or identical genes with predominantly additive effects on germination under both low and high temperatures. In the second approach, the effectiveness of directional phenotypic selection to improve tomato cold tolerance during germination was evaluated by selecting (in an F₂ population of the same cross) the fastest germinating seeds under low temperature and comparing the germination of the selected F₃ progeny with germination of an unselected F₃ population. The results indicated that selection was highly effective and significantly improved germination performance of the progeny; a realized heritability of 0.74 was obtained for low-temperature tolerance during germination. It is concluded that in these tomato lines germination under low temperature is genetically controlled, with additivity being the major genetic component, and thus the trait can be improved by phenotypic selection.     

不同世代温敏核不育水稻96-5-2S育性对低温的反应

为了探讨水稻光温敏核不育系临界温度遗传稳定性问题，以连续6个世代的温敏核不育水稻96-5-2S（从培矮64S中选育出的新株系）为材料，研究了它们育性对低温的反应差异。结果表明,(1)在它们育性转换敏感期用23.5℃恒温冷水处理10 d(水深20 cm左右)或遇到2～3 d平均日均温22.9～23.1℃(平均日最低温21.7～22.0℃)的自然低温时，所有世代的96-5-2S均表现不育, 自交结实率为0, 花粉可染率为0～0.9%，世代间差异不显著;(2)在它们育性转换敏感期用21℃、22℃恒温冷水处理10 d或遇到4 d平均日均温22.9℃(平均日最低温20.7℃)的自然低温时，所有世代的96-5-2S均表现可育, 自交结实率为0.2%～7.1%,花粉可染率为1.1%～19.5%，世代间存在差异,随繁殖世代增加,花粉可染率与自交结实率有逐渐上升的趋势,当繁殖到第5代时，花粉可染率显著提高，当繁殖到第6代时，自交结实率显著提高。(3)对照培矮64S（05株系）在相同低温条件下，花粉可染率与自交结实率均极显著高于各世代的96-5-2S。以上结果说明, 随繁殖世代增加,96-5-2S的临界温度会发生缓慢的遗传漂移，到第5、6代时，就会在花粉与结实水平上明显表现出来，但不同世代间临界温度的差异小于不同株系（96-5-2S与培矮64S-05株系）间临界温度的差异，据此认为，通过单株选择是降低光温敏核不育系临界温度的重要途径。     

Screening for grain dormancy in segregating generations of dormant × non-dormant crosses in white-grained wheat (<Emphasis Type="Italic">Triticum aestivum</Emphasis> L.)

Pre-harvest sprouting (PHS) in wheat (Triticum aestivum L.) is a significant problem. Introgression of genes controlling grain dormancy into white-grained bread wheat is one means of improving resistance to PHS. In this study seven dormant (containing the SW95-50213 and AUS1408 sources) × non-dormant crosses were produced to investigate the effectiveness of selection for grain dormancy in early segregating generations. Each generation (F₁–F₄) was grown in a temperature controlled glasshouse with an extended photoperiod (i.e. continuous light). F₂ and F₃ generations were subject to selection. Five hundred harvest-ripe grains were tested for germination over a 14 day period, and the 100 most dormant grains were retained and grown-on to produce the next generation within each cross. The response to selection was assessed through analysis of the time to 50% germination (G₅₀) in the F₂, F₃ and F₄ generations. In addition, changes in marker class frequencies for two SSR markers (barc170 and gpw2279) flanking a known quantitative trait locus (QTL) for grain dormancy on chromosome 4A were assessed in DNA from F₂ plants selected from early germinating (non-dormant) and late germinating (dormant) phenotypic extremes within each cross. Selection for grain dormancy in the F₂ and F₃ generations effectively recovered the dormant phenotype in all seven crosses, i.e. the F₄ generation was not significantly different from the dormant parent. Further, selection based on individual F₂ grains changed marker class frequencies for the 4A dormancy QTL; in most cases eliminating the marker class homozygous for the non-dormant alleles. Application of this screening method will enable breeders to better select for grain dormancy and may lead to development of new cultivars offering effective resistance to PHS in the near future.     

Shortening generation times for winter cereals by vernalizing seedlings from young embryos at 10 degree Celsius

Methods allowing quick generation cycles are available for various crop species but are limited to spring genotypes. However, winter types predominate in many crops including wheat and barley. Different from spring ones, winter genotypes need to be treated in low temperature for extended periods to accelerate flowering. Combined with known factors that reduce generation cycles for spring wheat and barley, the generation cycle effects of vernalizing seedlings from young embryos of winter types at 10°C of several crop species were studied. Here, we described how to obtain up to seven generations of winter barley, six generations for winter wheat or five generations for both winter oat and triticale genotypes per annum. This procedure should find wide applications in breeding and other biological studies.