大蒜发芽叶培养体细胞胚发生

将大蒜发芽叶培养于ＭＳ（１／２ＮＨ４ＮＯ３＿＋２，４－Ｄ２ｍｇ／Ｌ＋ＫＴ０．５ｍｇ／Ｌ上，形成愈伤组织。愈伤组织继代后，转移到ＭＳ（ＫＮＯ３２５２５ｍｇ／Ｌ＋（ＮＨ４）２ＳＯ４１６５０ｍｇ／Ｌ，无ＮＨ４ＮＯ３）＋ＫＴ２ｍｇ／Ｌ＋６－ＢＡ４ｍｇ／Ｌ＋Ａｄｅｎｉｎｅ２ｍｇ／Ｌ＋ＩＡＡ０．０１ｍｇ／Ｌ培养基上，２５天后，形成体细胞胚并能再生植株。其中，胚状体发生的必要条件是ＮＯ３／ＮＨ＾＋４＞１，ＫＴ／     

棉属[AG]与[AD]两个复合染色体组种间杂种的同工酶与核型研究

利用聚丙烯酰胺凝胶电泳法对人工合成的［ＡＧ］复合染色体组的异源四倍体与［ＡＤ］复合染色体组的陆地棉、海岛棉、夏威夷棉、黄褐棉的种间杂种Ｆ１及其亲本进行了过氧化物酶同工酶和细胞色素氧化酶同工酶分析，并对三元杂种［Ａ２×Ｇ１］ ×［ＡＤ］１及其亲本进行了核型分析。结果表明：（１）异源四倍体的基因转移到了杂种后代，并得以表达；（ ２）三元杂种［Ａ２ × Ｇ１］ ×［ＡＤ］１的核型公式为 ２ｎ＝ ４ｘ＝ ５２＝ ２Ｍ ＋ ４４ｍ（ＳＡＴ）＋６ｓｍ（ＳＡＴ），属于１Ｂ类型。     

普通小麦—顶芒山羊草异源附加系的创建和鉴定：Ⅰ.小麦花药培养对创建…

通过顶芒山羊草（Ａｅｇｉｌｏｐｓｃｏｍｏｓａ２ｎ＝２ｘ＝１４，ＭＭ）与波斯小麦（Ｔｒｉｔｉｃｕｍｐｅｒｓｉｃｕｍ２ｎ＝４ｘ＝２８，ＡＡＢＢ）杂交，人工合成遗传上相对稳定的双二倍体（２ｎ＝６ｘ＝４２，ＡＡＢＢＭＭ），以此为桥梁，与普通小麦（Ｔｒｉｔｉｃｕｍａｅｓｔｉｖｕｍ）品种“欧柔”进行正反杂（回）交，借助花药培养过程中能产生非整倍单倍体和非整倍双倍体的特点，在改良Ｃ１７固体培养基上上接种花药，诱     

小扁豆核型的比较分析

采用去壁低渗火焰干燥法制备小扁豆染色体标本观察其核型,结果表明,绿小扁豆和红不扁豆的核型公式均为２ｎ＝２ｘ＝１６＝１６ｍ＋６ｓｍ＋２ｓｔ＋２ｓｔ（ＳＡＴ）,两种小扁豆的核型类型都是３Ｂ,染色体相对长度系数组成均为２ｎ＝２ｘ＝１６＝４Ｌ＋６Ｍ２＋６Ｍ１＋４Ｓ,二者主要在第７号染色体臂比和２号染色体大小方面有明显差异。     

小麦新品种皖麦29

小麦新品种皖麦２９皖麦２９是安徽省农科院作物所育成的高产、稳产、多抗小麦新品种。亲本组合为（一粒小麦×阿夫乐尔）Ｆ０３３伦琴射线处理／ＮＰＦＰ－５４４２／３／ＡＬＯＮＤＲＡ“Ｓ”／４／２４１１／矮丰３号／／７６７９－２９－２－２。采用辐射诱变与复合杂...     

甘蓝型油菜-埃塞俄比亚芥二体附加系植株形态及细胞学鉴定

从甘蓝型油菜品种“３－６３－４－５－１”与埃塞俄比亚芥品种“Ｄｏｄｏｌｌａ”杂种Ｆ１植株开放受粉获得的Ｆ２群体中筛选出一株半不育、矮杆、甘蓝型油菜类型植株，经连续４个世代自交、分离鉴定出一个二体附加系“９２Ｉ１０９６”。细胞学观察结果，其根尖细胞染色体数２ｎ＝４０，比其母本甘蓝型油菜（２ｎ＝３８）多两条额外染色体。花粉母细胞（ＰＭＣｓ）减数分裂中期（ＭＩ）染色体构型平均为０．４７Ｉ＋１９．７７Ⅱ，     

4D缺体小麦与八倍体小偃麦杂交的细胞遗传学研究

利用自花结实的４Ｄ缺体小麦作母本，与中２、中５及中１００１等八倍体小偃麦杂交，获得的杂种Ｆ１植株除４Ｄ缺体×中５育性极低外，其余组合略低于普通小麦×八倍体小偃麦的自交结实率。杂种Ｆ１体细胞２ｎ＝４８。４Ｄ缺体×中２的Ｆ１花粉母细胞减数分裂ＭＩ染色体配对的平均构型为１８．８１（１５－２２）Ⅱ＋０．５７（０－３）Ⅲ＋０．１１（０－２）Ⅳ＋８．２３（６－１０）Ⅰ。观察结果同时表明：（１）单价体的分布在每个ＰＭＣ中以８为众数；（２）单价体之中的两个在多数的ＰＮＣｓ中能形成次级联合配对，说明４Ｄ与４Ｅ染色体具有部分同源关系；（３）杂种Ｆ１多数花粉母细胞中多价体的出现表明八倍体小偃麦中Ｅ染色体组具有促进部分同源染色体配对的基因。     

苄基腺嘌呤对小麦幼苗乙醇酸氧化酶和过氧化氢酶活性的影响

本研究结果表明,用２０－１４０ｍｇ／Ｌ的苄基腺嘌呤（ＢＡ）喷施小麦幼苗２天后,体内乙醇酸氧化酶活性比对照提高１０．７８－６４．７１％,其正相关系数是ｒ＝０．９８３９,其直线回归方程是Ｙ＝０．１００７＋０．０００４８Ｘ。用２０－１４０ｍｇ／Ｌ的ＢＡ喷施小麦２天后,体内过氧化氢酶活性比对照提高１３．６２－２４．２７％,正相关ｒ＝０．９０１５,２０－１００ｍｇ／Ｌ的ＢＡ处理２天后,蛋白质含量升高１４．６     

稻属间杂种花粉植株的细胞遗传学研究

以栽培稻０２４２８与紧穗野生稻间不育Ｆ１杂种（２ｎ＝２４，ＡＣ）为材料进行花约培养，共接种花约３２６８８个，获得再生绿苗１３株及白化苗两株，愈伤诱导率与分化率分别为０．１４％和３４．７８％。有９朱花粉绿苗长至成熟，均表现长芒、紫柱头、强感光及易落粒等野生亲本的特性。细胞学结果进一步表明，其中４株为二倍体（２ｎ＝２４），形态上琚的Ｆ１杂种相似，花粉母细胞中期Ⅰ亦只能见到少数二价体；另５株则为四倍体（     

甘薯和Ipomoea lacunosa的种间体细胞杂种植株再生及鉴定

用ＰＥＧ融合法融合甘薯品种高系１４号和近缘野生种Ｉｐｏｍｏｅａ ｌａｃｕｎｏｓａ的原生质体，将融合原生质体培养在含有０．０５ｍｇ／Ｌ２，４－Ｄ和０．５ｍｇ／Ｌ ＫＴ的ＭＳ培养基上，愈伤组织迅速增殖。将其中的７０个愈伤组织培养在添加３．０ｍｇ／Ｌ ＢＡＰ的ＭＳ培养基上，并进一步培养在ＭＳ基本培养基上，获得９株再生植株。过氧化物酶同工酶、酯酶同工酶和ＲＡＰＤ分析表明，其中２株再生植株（ＫＬ１和ＫＬ３）     

A moving block evaluation technique for improving the efficiency of pedigree selection

Summary Pedigree seletion on the basis of moving block adjustment encompasses a two-phase cycle per year, i.e. family selection at a number of sites representing production environments for which adaptation is sought, and individual plant selection wihtin selected families at an extra site. Family selection within sites is based on moving blocks consisting of sets of contiguous plots, the number of which varies according to the chosen selection pressure. Families are unreplicated within each site and family selection across sites is based upon the family selection index F, i.e. the number of sites at which a particular family has been selected. The use of moving blocks for control of variation in growing conditions wihtin sites, and of the index F for exploiting genotype-site interaction early in the program, is expected to increase efficiency and to save time required to release a cultivar, as regional tests become unnecessary. In addition, the procedure allows screening an unrestricted number of families at any number of sites, in both self-and cross-fertilizing crops.     

Subset selection in plant breeding practive

Summary Selection decisions in variety testing should partly be based on statistical motives. Useful tools for this are subset selection procedures. These procedures can also be used when the performed experiment has an incomplete block design or when a series of regional trials is studied. Various selection rules serve different selection goals, but they all need so-called selection constants. Often, these constants have to be approximated by computer simulation. For this simulation, and also for the execution of the selection rules, software has been developed and is available. Some practical adjustments and modifications of subset selection in plant breeding practice are proposed. Finally, a case study of selection in sugar beet is presented.     

Some remarks on honeycomb selection

Summary Up to now the only experiences in favour of the method of honeycomb selection were reported by the spiritual father of the method, i.e., Fasoulas. Three other reports presented very moderate results. Possible causes for these contrasting results are discussed. Fasoulas' preference for growing the plants in the selection field in absence of competition is in conflict with the conditions in commercial crops where intragenotypic competition occurs. This preference is considered in comparison with the more popular preference for growing the plants in the selection field in presence of intergenotypic competition, which in turn also deviates from the conditions in a commercial field. It is suggested that at some degree of interplant competition the highest response to honeycomb selection will be obtained. Further, it is explained why the average of the phenotypic values of the six neighbours of a central plant may be an unreliable measure for the growing conditions for the central plant.     

Sporophytic and gametophytic recurrent selection for improvement of partial resistance to Alternaria leaf blight in sunflower (Helianthus annuus L.)

Alternaria leaf blight, caused by Alternaria helianthi Hanf., is one of the most important diseases of sunflower causing significant yield losses in several tropical countries. Yet, so far, only partial resistance for the disease has been discovered in the germplasm through conventional sporophytic selection. Therefore, the main objective of the present investigation was to compare sporophytic and gametophytic recurrent selection with the aim to enhance the level of resistance to Alternaria leaf blight. The base population was synthesized by random mating three populations- two interspecific derivatives involving different species of Helianthus and one germplasm accession based on their partial resistance to disease incidence. The base population was subjected to 1-2 cycles of both sporophytic and gametophytic selection. The gametophytic selection was practiced by applying pathogen culture filtrate to the stigma and style one hour before pollination. The selection response was measured by scoring the percent disease index at flowering, 15 days after flowering, and at physiological maturity and by quantifying economic yield gain. A significant reduction in mean per cent disease index values and a gain in seed yield were observed for both the types of selection cycles, but more so for gametophytic selection. The populations improved through gametophytic selection appear to be more promising as the pollen selection allowed the selection of rare favorable allelic combinations that would hardly be detected at the sporophytic level. A combination of gametophytic selection and conventional sporophytic selection should be considered as an effective tool in population improvement programs to achieve higher levels of resistance in relatively short time.     

Selection in Early Generations of Dried Peas, Pisurm sativum L.

Seed production in peas is limited by early and severe lodging and by a low multiplication rate and pea breeders have tried to overcome such disadvantages by growing plants in early generations widely-spaced against wire netting. Progenies of four pea crosses were each tested over a period of tour years to investigate whether single plant selection for quantitative characters, in particular grain yield, is efficient in such circumstances in the Is generation. Efficiency of selection was also studied for yield and yield related characters in the F₃ based on f₂ derived single plant progenies grown in unreplicated microplots. Early yield selection in the F₂ as well as in the F₃ proved to be of poor efficiency. Heritability values of all recorded traits were only slightly higher in the F₃ than in the F₂. Efficiency of yield selection could not be increased significantly in these early generations by indirect selection, either for single traits or for index traits. Possible reasons are discussed for the low efficiency of direct and indirect selection for grain yield in early generations and proposals are made for its improvement and for alternative selection strategies.     

药用植物太空育种研究进展

药用植物的品质决定中药产品的质量和疗效,而药用植物育种是提高中药材产量和质量的关键。太空育种作为一种新的育种技术近年来在药用植物研究领域得到重点发展。在查阅相关文献的基础上,归纳了近年来药用植物太空育种在生物性状、细胞学、有效成分变化、分子标记、安全性等不同方向的研究进展和基本结论,总结了国内外在该领域取得的工作成果,分析了药用植物太空育种的特殊性及其研究存在的问题。认为将太空育种用于药用植物新品种的选育,可加快药材品种选育进程,提高育种质量。目前在药用植物空间生物学、后代性状遗传稳定性和有效成分变化规律等方面研究欠缺,建议加强药用植物太空育种基础理论研究投入,明晰诱变因素和诱变机制,进一步提高育种预见性和育种效率;建立具有药用植物特点的综合评价系统和新品种审定体系;针对药用植物太空育种的安全性和空间环境处理后有效成分种类和含量变化问题开展风险评价研究。     

蜥蜴体色两性异形的研究进展

为了弄清蜥蜴体色两性异形形成的原因及其生物学意义,在现有文献的基础上,对中国蜥蜴中具有两性异形体色的种类进行总结和分析。结果表明：在中国的156种蜥蜴中,有6科28种蜥蜴存在体色两性异形,占17.9%。这种体色的两性异形与环境变化和自身因素均有一定的关系,一般具有求偶炫耀、躲避攻击和隐蔽伪装的作用。因此,对蜥蜴体色两性异形的研究将为动物体色的着色机理及分化提供理论依据,并对视觉信号的形成及配偶选择的行为学、生理学基础提供参考。     

Single and Multiple Traits Selection in a Segregating Population of Wheat, Triticum aestivum L.

The breeding materials used in this study were the F₃, F₄ and F₅-generations of the cross between Giza 158 × Sonora 64 (Triticum aestivum L.). The objective of this study was to compare the relative merits of Smith-Hazel, desired gain selection indices, independent culling levels and single trait selection in improving grain yield, heading date and several agronomic traits. Highly significant differences among F₃ families and a satisfactory genotypic coefficient of variability were obtained for all the traits studied. The genotypic correlations were high between yield and each of spike weight, kernels/spike and spikes; plant, intermediate with 1000 kernel weight and very low with heading date, plant height and spike1 length-After two cycles of selection, the results of the gains realized indicated that the most effective method for improving yield was the Smith-Hazel index (SH₇) of seven traits followed by the desired gain index of seven traits (DG₇), SH₅, independent culling levels, DG₅ and direct selection (or grain yield/plant. Direct selection for heading date, plant height and spike length was the best method for improving these traits, but undesirable correlated responses in the other traits were obtained.     

Multistage selection indices for maximum genetic gain and economic efficiency in red clover

Selection index updating, a method of multistage selection, allows breeders to determine the optimal truncation point of each stage so that the aggregate genetic gain (▵H) or the gain to cost ratio (▵H/C) is maximum. In this study, we demonstrated the use of selection index updating on selection of red clover (Trifolium pratense L.). We determined the optimal selection schemes that optimized the balance between cost saving and lowered genetic gain in multistage selection. A total of 78 red clover half-sib families were evaluated for petiole length (PL), seedling vigor (Vig) measured at the seedling stage, and canopy height and individual plant dry weight recorded on initial growth (CH1 and DW1) and regrowth (CH2 and DW2). Alternative selection schemes with different number of stages, traits, and proportions selected at various stages were examined to maximize either ▵H or ▵H/C. Single stage index selection had a greater predicted genetic gain than multistage selection, but it was also associated with higher costs. Early culling at the seedling stage resulted in significant cost savings and increased gain to cost ratio. The ratio was 9.857 or more with early culling and 3.062 or less without seedling selection. The most efficient selection programs consisted of PL, Vig, DW1, and DW2. Inclusion of CH1 and CH2 into the selection indices did not contribute to the increase of the total genetic gain, nor to the increase of the ratio. This revised version was published online in July 2006 with corrections to the Cover Date.