不同磷化氢抗性的赤拟谷盗亚致死浓度下生长发育比较

在室温30℃±2℃、相对湿度75％±50环境中研究了对磷化氢抗性和敏感的赤拟谷盗3个品系在磷化氢亚致死浓度下卵、幼虫和蛹的发育与死亡情况,3个赤拟谷盗品系对磷化氢的抗性系数分别为R1=1、R170=170和R247=247,研究中设定的磷化氢亚致死浓度分别为0mg／L、0．0028mg／L和0．014mg／L。主要结果为：磷化氢亚致死浓度下赤拟谷盗抗性和敏感品系的发育历期延长;亚致死浓度磷化氢熏蒸下,3个品系间幼虫发育速率差异不明显,但抗性品系卵期和蛹期的发育速率增加较敏感品系显著。在亚致死浓度下,赤拟谷盗敏感品系的卵、幼虫和蛹的死亡率增加都明显高于抗性害虫,抗性品系的存活能力明显大于敏感害虫。     

阿维菌素和阿维·吡虫啉对马铃薯桃蚜的亚致死效应

为了明确阿维菌素和阿维·吡虫啉不同亚致死剂量对马铃薯桃蚜F₀代成蚜和F₁代的干扰作用。通过在室内组建不同亚致死剂量下马铃薯桃蚜生命表的方法,分析了不同亚致死剂量对马铃薯桃蚜繁殖、发育和种群参数的影响。结果表明：用阿维菌素和阿维·吡虫啉LC₁₀、LC₂₅、LC₄₀分别处理马铃薯桃蚜成蚜后,成蚜的平均产蚜量显著小于对照,其平均寿命也显著短于对照。其中阿维·吡虫啉LC₄₀组的平均产蚜量最低,为9.52头,平均寿命最短,为8.07天。与对照组相比,F₁代的若蚜期显著延长,成蚜期显著缩短。对F₁代种群参数的影响体现在,净增殖率(R_o)、内禀增长率(r_m)以及周限增长率(λ)都显著降低,种群加倍时间(D_t)显著延长。即阿维菌素和阿维·吡虫啉不同亚致死剂量处理亲代成蚜后,会明显抑制其寿命和产蚜量,同时也可以有效控制F₁代种群再猖獗。     

甲氧虫酰肼对斜纹夜蛾亚致死效应研究

 在室内研究了甲氧虫酰肼对斜纹夜蛾的亚致死效应。结果表明,亚致死剂量甲氧虫酰肼能抑制斜纹夜蛾幼虫的生长发育,显著降低产卵量和孵化率。此外,研究还发现,亚致死剂量甲氧虫酰肼对斜纹夜蛾酯酶、多功能氧化酶和谷胱甘肽S-转移酶具有一定的诱导作用。与对照相比,LC₁₀剂量甲氧虫酰肼处理斜纹夜蛾24 h后以及LC₃₀剂量处理48 h和96 h后,酯酶活性显著提高;LC₁₀剂量处理24 h后,多功能氧化酶活性显著提高;LC₃₀剂量处理96 h后,谷胱甘肽S 转移酶活性显著提高。     

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。     

转Bt基因水稻对水稻螟虫和稻纵卷叶螟的抗性

为明确转cry1Ab／cry1Ac基因汕优63水稻（汕优63／Bt水稻）对靶标害虫一二化螟、三化螟和稻纵卷叶螟的控制效果．通过室内生物测定和田间观察的方法对汕优63／Bt水稻对二化螟的致死性及其对三化螟和稻纵卷叶螟的抗虫效果进行了研究。室内离体植株测定结果表明,汕优63／Bt水稻对二化螟具有很好的抗性,1龄幼虫取食汕优63／Bt水稻48h和72h后的死亡率由31．5％上升到95．6％。3龄幼虫的死亡率由2．7％上升到67．9%。汕优63／Bt水稻对1龄幼虫的致死效应高于3龄幼虫,但没有二化螟能在汕优63／Bt水稻上完成世代发育。在田间。三化螟和稻纵卷叶螟在汕优63／Bt水稻上造成的白穗率和卷叶率分别为0.38％和0．24％。显著低于对照。表现出良好的抗虫性。     

惰性粉杀虫剂对黄粉虫成虫的物理伤害症状研究

用一种以食品级惰性粉为主要原料的惰性粉杀虫剂处理黄粉虫成虫,处理6h～8h、12h～14h、24h～26h和48h～50h试虫的平均爬行速度分别为12mm／s、7mm／s、3mm／s和0．4mm／s,明显比正常试虫的爬行速度（33mm／s）慢（p〈0．05）;处理后试虫表现出一系列物理伤害症状,随处理时间的延长,试虫受伤害程度增强。根据惰性粉杀虫剂处理后试虫爬行速度、伤害症状和死亡时间,将试虫的伤害程度由轻到重划分为四个级别,伤害一级：试虫平均爬行速度为10mm／s-15mm／s,死亡时间为74h±6h,身体抬高,腿节和胫节之间的活动角度略有减小;伤害二级：爬行速度为5mm／s-10mm／s,死亡时间为42h±5h,偶尔绊脚,摔倒后能立即站立起来继续爬行,腿节和胫节之间的活动角度进一步减小,胫节和附节之间的活动角度也减小;伤害三级：爬行速度为1～5mm／s,死亡时间为20h±1h,附节和爪不能牢固的抓住滤纸,摔倒频率明显增加,且摔倒后较难重新站立,腿节和胫节之间、胫节和附节之间的活动角度都较小;伤害四级：爬行速度小于1mm／s,死亡时间为5h±1h,腿节和胫节之间、胫节和附节之间基本不能活动,不能爬行,摔倒后基本上不能再站立起来。结果表明,目前被广泛接受的惰性粉破坏虫体表皮蜡层导致失水致死和堵塞气门致死的理论并不能完全解释这种食品级惰性粉杀虫剂作用害虫的症状并较快致死害虫的机理,其杀虫机理还有待于进一步的揭示。     

落叶松尺蠖核型多角体病毒毒力的生物测定

落叶松尺蠖核型多角体病毒感染落叶松尺蠖幼虫死亡的回归直线方程为Y=1.9621+0.5056x,LD_(50)=10~(6.01);在一定时间内幼虫死亡率随感染日期的增加而提高;LT_(50)随感染浓度的增加而减少;EaNPV的毒力随着保存时间延长而逐渐降低,存放24个月的病毒较保存11月的病毒毒力降低36.5—58.5%;日光照射病毒被灭活的程度随阳光照射时间的增加而增加;存留在松树干上一年的EaNPV仍保留有一定的活性,与保存于冰箱中的病毒比较,其毒力降低63.2%;EaNPV致病死亡的2、3、4、5龄的落叶松尺蠖幼虫及蛹的多角体含量平均分别为每头虫0.966亿,2.675亿,5.335亿,6—15亿及1.766亿;用EaNPV1×10~7PIB/ml与1×10~8PIB/ml感染菜青虫、粘虫、玉米螟、棉大卷叶螟、杨枯叶蛾和柳毒蛾幼虫,均不引起幼虫发病.     

外源MeJA诱导玉米抗性对亚洲玉米螟生物学特性的影响

为明确茉莉酸甲酯(methyl jasmonate,MeJA)诱导玉米幼苗产生抗性对亚洲玉米螟(Ostrinia furnacalis)生物学特性的影响,测定了玉米幼苗在4种浓度的外源MeJA处理后对亚洲玉米螟幼虫生长发育和成虫繁殖情况,并利用生命表方法研究了饲喂MeJA处理后的玉米幼苗对次代亚洲玉米螟实验种群的影响。结果表明：取食外源MeJA诱导的玉米幼苗后,亚洲玉米螟幼虫死亡率增加,发育历期延长,成虫寿命缩短、产卵量下降,除了100 μmol/L MeJA处理组蛹重高于对照外,其他处理亚洲玉米螟体重与蛹重均降低,影响程度与MeJA的浓度有关。225 μmol/L MeJA诱导处理后的玉米幼苗对亚洲玉米螟生长发育影响最大,与对照组相比,幼虫历期长了5.41天,成虫寿命减少1.33天,产卵量减少3.6头。MeJA的诱导抗性显著影响了亚洲玉米螟幼虫对玉米幼苗的取食,100 μmol/L和225 μmol/L MeJA处理组与对照组虫体体重相差3.29~6.86 mg,达到统计学差异,生长抑制率达28.34%~59.09%。对次代种群的影响表现在净生殖率(R0)、周限增长率(λ)降低,内禀增长率(rm)由0.0725降至0.0502,平均世代周期(T)和种群加倍时间(Dt)较对照显著延长。这些结果表明MeJA处理玉米幼苗能够降低亚洲玉米螟的发育速率,这将对亚洲玉米螟的综合防治具有重要的指导意义。     

锌、锰对棉花吸收氮、磷养分的影响及机理研究

较高或较低浓度的土壤锌、锰影响棉花对氮、磷养分的吸收、而合适的土壤锌、锰浓度能促进棉花根系和地上部对氮、磷的吸收和积累。提高植株及茎、叶、蕾、铃中氮、磷的含量,对棉花的生产发育,产量及产量构成因素都表现出明显的促进作用,通过水培试验研究发明,锌、锰在一定浓度条件下所表现的促进作用,主要是提高了棉花植株的根系活力,增加棉株叶片的叶绿素含量,调节棉株体内的酶活性,从而增加了棉花对营养物质的吸收、运输和代谢、提高了氮、磷的利用率、增加棉花的产量。     

异色瓢虫对菜缢管蚜、禾谷缢管蚜和白杨毛蚜捕食的作用

异色瓢虫是一种重要的捕食性天敌,可捕食多种蚜虫,在生物防治中具有很大应用前景。研究了异色瓢虫对3种蚜虫(即菜缢管蚜、禾谷缢管蚜和白杨毛蚜)的捕食功能反应。结果表明：异色瓢虫对3种蚜虫的日捕食量中,其中四龄幼虫最大,成虫和三龄幼虫次之,1、2龄幼虫最小。捕食者对猎物的功能反应均属于Holling-Ⅱ型方程。     

Synthesis of somatic hybrids (RCBB) by fusing heat-tolerant Raphanus sativus (RR) and Brassica oleracea (CC) with Brassica nigra (BB)

Brassica carinata (BBCC), a potential oilseed crop for dry land agriculture, is sensitive to high temperatures during germination and early stages of growth, which thereby restricts the possibility of using the residual soil moisture available after the rainy season for its cultivation. To overcome this problem, a three‐genome hybrid, RCBB, was synthesized using Raphanus sativus (RR) and Brassica oleracea (CC) as donor sources for the desired heat tolerance. Protoplasts of RC hybrids obtained through sexual crosses between R. sativus (female) and B. oleracea (male) were fused with protoplasts of Brassica nigra (BB) to produce RCBB somatic hybrids. The hybrid colonies regenerated with an average frequency of 7.6%. Twelve out of 36 hybrids grown to maturity were characterized for their nuclear and organelle genomes. While all the hybrids showed the presence of B. nigra chloroplasts, 10 of the hybrids showed B. nigra‐specific mitochondria and two had Raphanus‐spedfic mitochondria. The somatic hybrids could be backcrossed to B. carinata.     

Origin and evolution of teosinte (Zea mexicana (Schrad.) Kuntze)

Summary The tripartite hypothesis postulates that cultivated maize was derived from a wild podcorn which was once indigenous to the lowlands of South America; that this wild Z. mays is now extinct; that Z. mexicana (teosinte) originated from natural hybridization of Z. mays and a species of Tripsacum after cultivated maize was introduced into Central America; and that most modern races of maize resulted from introgression of primitive maize with teosinte, Tripsacum, or both. This hypothesis has been criticized primarily on the basis that it involves too many theories for the available facts.The basic question that needs to be answered is whether maize was domesticated from a wild Z. mays or from Z. mexicana. The oldest known archaeological remains suggest that a wild Z. mays existed before Z. mexicana came on the scene. This question can only be settled by further archaeological research.Accepting the assumption that a species of Zea which is distinctly different from Z. mexicana gave rise to maize, however, does not necessarily lead to accepting a hybrid origin for teosinte. Judging from present day breeding behaviour, Z. mays and Z. mexicina are conspecific and only distantly related to Tripsacum. This cytogenetic similarity could be explained on the basis of extensive introgression between teosinte and maize. Introgression of germplasm from teosinte into maize is obvious wherever these taxa are sympatric. This pattern of a crop absorbing genes of its wild progenitor across a weedy race, is commonly encountered in all other cereals. Should this not be true in maize, it certainly will be a rare exception.The assumption that teosinte originated as a hybrid between domesticated Z. mays and a species of Tripsacum remains an intriguing possibility. However, after weighing the pros and cons of the available morphological and genetical evidence, the level of confidence with which this hypothesis can be excepted appears rather low.     

异色瓢虫对菜缢管蚜、禾谷缢管蚜和白杨毛蚜的捕食作用

异色瓢虫是一种重要的捕食性天敌,可捕食多种蚜虫,在生物防治中具有很大应用前景。研究了异色瓢虫对3种蚜虫(即菜缢管蚜、禾谷缢管蚜和白杨毛蚜)的捕食功能反应。结果表明:异色瓢虫对3种蚜虫的日捕食量中,其中四龄幼虫最大,成虫和三龄幼虫次之,1、2龄幼虫最小。捕食者对猎物的功能反应均属于Holling-Ⅱ型方程。     

N-(1-萘乙酰基)-N'-(4-氨替吡啉基)硫脲(NAT)对小麦生理活性影响的初步研究

以新合成的NAT配制成不同浓度(0.1、1.0、10.50mg·L~(-1))的水溶液,对小麦进行漫种、水培幼苗和大田灌浆期叶面喷洒处理,以与NAT相同浓度的NAA作对比,研究了喷后一定时期小麦叶片生理活性和收割时籽粒千粒重。结果表明,NAT使小麦在不同生长发育时期叶片中的叶绿素含量均增加;幼苗叶片呼吸速率下降;幼苗期低浓度处理NR活性增高,高浓度显著抑制,灌浆期则随处理浓度的升高而显著增加;籽粒千粒重明显高于对照。不论对叶片生理活性还是对籽粒千粒重的影响,NAT的总体效果均明显优于NAA,其中以1 mg·L~(-1)左右浓度的NAT处理效果最佳。     

香菇新品种L934和L937的培育

用香菇Ｌ８６７与Ｃｒ０４两品种单核菌丝体配对杂交，培育出Ｌ９３４；用香菇Ｌ３３与Ｃｒ０４两品种单核菌丝体配对杂交，培育出Ｌ９３７。拮抗实验和酯酶同工酶实验完全证实与它们与杂交亲本的不同，从而确认Ｌ９３４和Ｌ９３７为两个各自独立的香菇新品种。     

Seasonal distribution of young sole (Solea solea (L.)) in the nursery ground of the bay of Vilaine (Northern bay of Biscay)

The distribution of young sole was studied in the bay of Vilaine nursery ground as a function of age and season for the 0, 1 and 2-groups. During 1988 and 1989, bimonthly trawl surveys were carried out from the estuary to the 50-m-isobath along a 65-km transect. A regular seasonal pattern demonstrated two combined trends. An offshore movement is observed with increasing age; this general trend is marked by an inshore migration in spring and an offshore one in winter. The fluctuations of the distribution pattern are discussed in relation to sedimentary characteristics, to trophic requirements and to hydroclimatic variations. The main conclusion is that young soles are concentrated inside a closed nursery area. In their third winter some participate in spawning migration and they get mixed, to a certain extent, with newly recruted soles from nearby nursery grounds.     

Cu~(2+)、Mg~(2+)、Fe~(2+)对绿豆干物质积累及产量的影响

2010-2011年对白绿9号进行了Cu SO4、Mg SO4、Fe SO4溶液(浓度均为50mmol/L)浸种、喷施、浸种+喷施、蒸馏水(CK)4种处理试验。探讨Cu2+、Mg2+、Fe2+对绿豆根系、茎秆、叶片干物质积累分配及产量性状和产量影响,目的是指导绿豆高产栽培。试验结果:不同处理对干物质积累等的促进作用为浸种浸种+喷施喷施;从离子作用上看,Mg2+Fe2+Cu2+。     

Utilization of flow cytometry for festulolium breeding (Lolium multiflorum (2x) × Festuca arundinacea (6x))

Festulolium is a hybrid between Festuca and Lolium species that has valuable agronomic traits from both grass species. The purpose of our breeding program is to produce hexaploid festulolium that introduces tolerance to summer depression into Italian ryegrass (Lolium multiflorum) by crossing it with tall fescue (Festuca arundinacea). However, we found the DNA ploidy of hexaploids was not stable and was reduced in successive generations. We aimed to find out how to obtain stable high-ploidy festulolium. F1 hybrids of L. multiflorum and F. arundinacea were produced. The F3 generation was produced from putative hexaploid F2 individuals by open pollination. The F4 to F6 generations were obtained by polycrossing. The DNA ploidy levels of F2 to F6 individuals were estimated by flow cytometry. Cytological characteristics of the F5 and F6 individuals were investigated by FISH and GISH. The DNA ploidy level of hexaploid festulolium was reduced and stabilized at almost the same level as a tetraploid. Seed fertility was inversely correlated with an increase in ploidy level. GISH revealed no preferential Lolium transmission. FISH with a telomere probe revealed that counting the exact number of chromosomes in festulolium was difficult. DNA ploidy level was strongly correlated with the number of chromosomes.