京郊西兰花小菜蛾的田间防治药剂筛选与评价

为评价高效氯氰菊酯、溴氰虫酰胺、苏云金杆菌、甲氨基阿维菌素苯甲酸盐、乙基多杀菌素等5种杀虫剂对小菜蛾的田间药效,本文采用喷雾法进行了田间试验。结果表明,10%溴氰虫酰胺可分散油悬浮剂、6%乙基多杀菌素悬浮剂对小菜蛾在药后1~7 d的防效较好;32000 IU/mg苏云金杆菌可湿性粉剂、32000 IU/mg苏云金杆菌可湿性粉剂与10%溴氰虫酰胺可分散油悬浮剂分别按50%推荐用量组成的1∶1的混配剂,药后1 d的防效仅在60%左右,速效性较差,但是药后3~7 d的防效较好。其中,混配剂药后3 d的防效高达90.70%。5%甲氨基阿维菌素苯甲酸盐水分散粒剂和4.5%高效氯氰菊酯乳油在药后1~7 d的防效均较差。因此,在西兰花生产上可使用减量的溴氰虫酰胺与苏云金杆菌混配剂进行小菜蛾的防治,以达到农药减量增效防治小菜蛾的目的;在小菜蛾暴发时,可使用溴氰虫酰胺或乙基多杀菌素,以达到迅速防治的目的。     

河北植物新增补属、种与入侵物种新分布

报道了《河北植物志》与《河北高等植物名录》未记录的植物1属3种1变种。其中拔毒散(Sida szechuen-sis Matsuda)、偃狗尾草[Setaria viridis(L.)Beauv. var. depressa(Honda)Kitag.]在河北省首次记录。     

青花菜锌指蛋白基因BoCCCH1的克隆和表达分析

CCCH锌指蛋白广泛存在于真核生物中,在植物的生长、发育和逆境胁迫响应中起着重要作用。为获知青花菜CCCH转录因子基因的序列特征和表达特性,从青花菜叶片中克隆到1个CCCH基因,命名为Bo CCCH1,同时,利用RT-PCR方法研究了其在不同器官及霜霉菌侵染叶片中的表达模式。序列分析结果表明,Bo CCCH1的基因组全长为1 568 bp,包含1个长度为599 bp的内含子,2个长度分别为627 bp、342 bp的外显子,编码322个氨基酸,蛋白质的分子量与等电点分别为35 296.42 Da和8.47;Bo CCCH1有2个锌指结构,类型均为C-X8-C-X5-C-X3-H。系统发育分析结果表明,Bo CCCH1与其它植物的21条同源序列在进化树上分为6组,来自十字花科的CCCH与Bo CCCH1处于同一分支。基因表达结果表明,Bo CCCH1在叶、花茎、嫩角果、花蕾和花中表达,其中花茎和嫩角果的表达量最高,但在根中未检测到表达;在霜霉菌侵染下,叶片Bo CCCH1的表达量升高,到24 h和36 h时达到最大,推测Bo CCCH1与霜霉病抗性相关。本研究为进一步探明Bo CCCH1在霜霉病抗性反应中的功能奠定了基础。     

Genetic variation in seed production and its components in four cultivars of the pasture grass Setaria sphacelata

Variation in seed production and its components was investigated between and within four cultivars of the pasture grass Setaria sphacelata, in two experiments over two years, as a basis for future cultivar improvement. The study sought to determine the basis for the considerable differences in seed production of the four cultivars Nandi, Narok, Solander and Kazungula, to determine the extent of genetic variation in the four cultivars in attributes which contribute to seed yield, and to investigate genotypic consistency in seed production over years and seasons. Each experiment comprised 50 genotypes of each cultivar. In the first experiment, plants were harvested a set number of days after median flowering date whereas in the second experiment, which was unreplicated, each genotype was harvested a set number of days after it had flowered. In the first experiment, seed yields were generally highest for Kazungula, lowest for Narok and intermediate for Nandi and Solander. All measured attributes contributing to seed yield exhibited a high order of variation between and within cultivars, but the basis for the large difference in seed yield per plant between cultivars was tiller fertility rather that total tiller number. Averaged over the four harvests, there was a six fold to > 100–fold intra-cultivar genetic range in seed production, associated with differences in tiller fertility, which were associated with differences in date of first flowering. Broad sense heritability for seed yield averaged 0.68 for the four cultivars and showed little change over the four harvests. Genotypes which produced high seed yields in summer were also more productive of seed in autumn and the 0ore productive genotypes in the first year were also more productive in the second year. Cultivars differed in the relative importance of factors which contributed to the high seed yield of high-yielding genotypes. In the second experiment, genotypes with a high seed yield also generally had the highest tiller fertility, even though all genotypes were harvested the same number of days after first flowering. Within-cultivar correlations in seed yield between the two experiments were generally significant and the elite 20% of genotypes from this experiment had 1.2–2.9 times the seed yield of the same genotypes with a very different harvesting regime in the first experiment. It is concluded that opportunities exist in all four cultivars for improvement in seed production and that the selection criterion offering the best opportunity for advance would be fertile tiller number. In Narok, Solander and Nandi, this would result in increased tiller fertility, whereas in Kazungula, it would result in an increase in total tiller number. This revised version was published online in July 2006 with corrections to the Cover Date.     

Inheritance of sethoxydim resistance in foxtail millet, Setaria italica (L.) Beauv.

Interspecific hybridization between foxtail millet cultivars (Setaria italica) and a green foxtail (S. viridis) resistant to the herbicide sethoxydim were undertaken to breed foxtail millet for improved herbicide resistance. Parents, reciprocal F₁ hybrids, F₂ selfed derived populations and BC₁ backcross progeny were produced and analysed for mortality and fresh weight over a range of dosages. All resistant progeny were 700 times more resistant than susceptible cultivars and was symptom free under current field dosages. Segregations of resistant and susceptible progeny (3:1 in F₂ and 1:1 in BC₁) were not dependent upon dosage. Heterozygous individuals displayed the same magnitude of resistance as homozygous plants at twelve times the recommended field dosage. Results suggested that sethoxydim resistance in foxtail millet was controlled by a single, completely dominant, nuclear gene. This revised version was published online in July 2006 with corrections to the Cover Date.     

Indentification of true genetic dwarfing sources in foxtail millet (Setaria italica Beauv.)

Summary True genetic dwarfs hither-to not reported have been located in foxtail millet. The dwarfs as a group distinguished themselves from the talls in having altered constellation of characters. The morphological differences were highly significant for plant height, internodal length, and tillering potential. The talls had elongated internodes compared to dwarfs while there was no difference for node number on the main stem suggesting that short internodal length was primarily responsible for dwarfism. The dwarfs also showed slightly higher leaf number per plant, leaf area and harvest index compared to talls. The dwarfs were insensitive to exogenous GA₃ application indicating that GA₃ synthesis is not impaired. This suggests that dwarfing gene sources presently identified are true genetic dwarfs and their behaviour is similar to dwarfs derived from Norin 10 in wheat and Dee-geo-woo-gen in rice. The superior morphological frame makes these dwarfs ideal as far as plant type is concerned and offers immense potentialities in breeding high yielding foxtail millets.     

Pollen-mediated gene flow in an autogamous crop: Foxtail millet (Setavia italica)

Gene How is a key concern associated with the eonlamination of seed multiplication iields and the use of transgenic crops. The release of herbicide-resistant germplasnis and the use of male-sterile varieties make foxtail millet (Sviaria ilalicii) an appropriate material to inves-tigate this concern. Pollen dispersal from pollen donor sources and gene tlow in fertile and male-slerile varieties of fortail millet were investigated in experiments in China and France. Although foxtail millel is mainly autogamous (less than 2% oiitcrossing), pollen from a 5m diameter plot could fertilize a tertile variety up to 24 ni away, and a male-sterile variety up to 40m. Negative exponential and WeibuU fnnctions were used to tit the relationships between percentage and number i.A iubrids per cm of ear with distance from the pollen source. Wind velocity and direction resulted in variations of gene How intensity, but did nol change liie slope ofthe regression equations. Pollen competition for available target ovules was observed up to 2 m away from a 1 m diameter pollen source. The percentage of pollen grains that fertilized ovules outside the pollen donor source was 1.4% of the total pollen grain produetion. For every iflO pollen grains released under lieid conditions 1.5 seeds were produced. The probability funetion of pollen dispersal for one donor plant was calculated. It allowed predictions of gene How accord-ing to lield shapes, estimations of isolation distances to preserve /ariety purity against pollen contamination, and the fornuiiation of efficient male/female ratios Ibr hybrid seed production.     

谷子(Setaria italica)Ch4n×法氏狗尾草(S.faberii)杂种幼胚培养及杂种F_1的鉴定

1989年,进行了谷子(Setaria italica)Ch4n×法氏狗尾草位(S.fabeiii)的远缘杂交和杂种胚培养。共接种已授粉子房264个,得到22株苗,仅11株成活。试管苗经继代培养和繁殖,得到了大量的小植株,移栽成活并发育到成熟。经形态学和细胞学鉴定,其中有两个株系是杂种,杂种F_1的染色体数为2n=4x=36,花粉母细胞在减数分裂中期Ⅰ染色体配对不正常,染色体构型为(18-2)Ⅰ+(13-0)Ⅱ+(0-9)Ⅲ+(0-3)Ⅳ,后期染色体分离不正常,形成不正常的四分体和微型小孢子,花粉败育。F_1高度不育,其形态特征介于双亲之间,植株在许多性状上都与父本法氏狗尾草相似,而与母本相差较远。