小白菜小孢子胚状体诱导影响因素研究

以10个小白菜杂交种为试材,采用游离小孢子培养方法,研究影响小孢子胚状体形成因素的结果表明,不同品种胚状体的诱导率不同;NLN培养基中大量元素减半有利于小孢子胚诱导,其诱导率达到100%;培养基中添加0.05 mg/L的6-BA和0.2 mg/L的NAA可以提高胚状体诱导率;活性炭和琼脂糖对诱导胚状体发生和发育有促进作用,可使子叶胚的比例达90%以上;花蕾经4℃低温预处理24 h后的成胚率显著提高.     

单倍体育种技术在油菜育种材料创新上的应用研究Ⅱ.胚状体培育及试管苗越夏

利用游离小孢子培养技术对9个甘蓝型杂交油菜品种(组合)的F1代进行离体小孢子培养.在NLN-13培养基中诱导胚状体发生,将胚状体放置于含有多菌灵和链霉素的培养基中培养,结果表明:①20mg/L浓度的多菌灵和链霉素可以提高胚状体的成苗率.②将胚状体接种于含有0.05mg/L 2,4-D和0.01mg/L6-BA的MS培养基中培养,愈伤组织能快速分化形成不定根和丛芽.     

花椰菜游离小孢子培养及植株再生研究

以186个花椰菜杂交品种及组合为试材,进行了游离小孢子培养研究。结果表明:基因型是胚状体发生的决定因素;24 h 32℃的高温前处理是胚状体发生的必须条件;单核靠边期到双核期的小孢子是进行胚状体诱导的最佳时期,胚状体发生频率最高;培养基中添加6-BA 0.1 mg/L,NAA 0.005 mg/L可以促进胚状体发育。将20 d的胚状体进行脱分化处理,可以大幅度提高胚状体的成活率,植株再生率为53%,再生植株中双单倍体占83.5%。     

菜心小孢子胚再生体系优化及植株倍性鉴定

为进一步优化菜心游离小孢子胚再生技术体系,本研究以3份不同基因型的菜心小孢子胚状体为试验材料,研究不同培养基类型、培养基中不同琼脂浓度和不同胚龄对胚再生的影响,并对再生植株进行倍性鉴定。结果表明,使用B5培养基时各基因型的成苗率均高于MS培养基,褐化率低于MS培养基,B5培养基是菜心小孢子胚状体再生的适宜培养基;培养基中添加适宜浓度的琼脂可提高再生植株的成苗率,随着琼脂浓度的增加,出苗率呈先升后降的趋势,琼脂浓度为1.0%时,各基因型的出苗率达到最高;胚状体再生的最佳胚龄是25～29 d,胚龄时间过长或过短均不利于胚状体出苗,其中40 d以上胚龄的胚状体几乎不出苗;倍性鉴定发现菜心小孢子再生植株中同时存在单倍体、二倍体和多倍体,3个基因型的二倍体自然加倍率在62.22%～71.11%之间;75 mg/L秋水仙素处理可提高菜心再生株系的二倍体率。本研究为菜心游离小孢子胚再生体系优化及再生植株倍性鉴定提供了技术基础。     

活性炭对小白菜游离小孢子培养的影响

以24个小白菜品种为材料,通过在NLN培养基中添加不同浓度活性炭,研究其对游离小孢子培养的影响.结果表明:在NLN-13培养基中添加活性炭(0.5 g/L),有利于小孢子胚的诱导和形成,供试材料(N4,N8)添加活性炭处理胚诱导率较未添加活性炭的处理分别提高19,66.5倍.采用添加活性炭(0.5 g/L)的NLN培养基对24份小白菜品种进行游离小孢子培养,有20份材料诱导出胚,培养成功率为83.3%.表明添加活性炭的培养基对小白菜游离小孢子培养有较好的效果.不同基因型间胚诱导率差别较大,每花蕾诱导胚数为0.4～86.7个.依据胚诱导率的高低可将其分为极易诱导、易诱导、难诱导和不能诱导出胚4类.B5 6-BA 0.2 mg/L NAA 0.02 mg/L 活性炭0.5 g/L 3%蔗糖 1%琼脂培养基有利于幼胚长成植株.     

火龙果花药培养诱导胚性愈伤组织及遗传稳定性

成年态火龙果茎段诱导的愈伤组织再分化较困难,进而影响到遗传转化效率。以红皮紫红肉的"紫红龙"火龙果花药为外植体,研究了小孢子不同发育时期、低温预处理时间、不同植物生长调节剂及浓度配比对花药诱导胚性愈伤组织的影响。结果表明,小孢子发育处于单核初期至单核靠边期的花药,其愈伤组织诱导率最高可达23.9%,但未能诱导出胚状体;而4℃低温预处理48 h,愈伤组织的诱导率可达32.8%;最适花药愈伤组织诱导的培养基为MS+2.0 mg/L 6-BA+1.0 mg/L 2,4-D+60 g/L蔗糖,诱导率为37.4%,胚性愈伤组织为黄绿色、致密状,外表有颗粒状突起。愈伤组织增殖培养基以MS+0.4 mg/L TDZ+0.8 mg/L KT效果较好,增殖系数达9.1倍以上。愈伤组织再分化培养基为MS+0.4 mg/L TDZ+0.5 mg/L 2,4-D+0.6 mg/L NAA时,愈伤组织再分化率达36.7%。通过火龙果花药诱导出愈伤组织,增殖获得大量胚性愈伤组织,再分化形成不定芽,经SRAP分子标记检测遗传性一致,能为火龙果基因工程育种和种苗快速繁育提供新的途径。     

春、夏大白菜花药培养胚状体诱导的影响因素研究

以13份春、夏大白菜为材料进行花药培养,研究几种因素对花药胚状体诱导的影响.结果表明,当花蕾长为2.0～3.0mm,花瓣与花药长度之比为1/2～4/5时,54%～70%的小孢子发育处于单核靠边期,最适合进行花药培养.花药培养结果表明,基因型不同,胚状体的诱导率有极大的差异,最容易形成胚状体的材料是126,诱导效率达13.71%;胚状体的出现在花药接种后的15～30d之间,培养后20d左右是胚状体出现的高峰期.培养基的种类对培养结果也有影响,其中以Keller培养基效果最佳,Keller培养基中有机成份加倍,则可以明显提高胚状体的诱导效率,培养基中10%的蔗糖浓度促进胚状体的诱导.     

提高油菜游离小孢子胚诱导频率的研究

以11个甘蓝型油菜基因型为材料,采用NLN培养基进行游离小孢子培养,对如何提高可培养的基因型范围和产胚率进行了研究。结果表明,11个油菜基因型中有10个基因型可以诱导出胚,培养成功率达90.9%,表明采用NLN培养基进行游离小孢子培养油菜基因型范围比较宽,但各基因型间小孢子胚产量差别很大,每花蕾产胚量为0.08~3.53个,TR4和TR9两个基因型每花蕾产胚可达3.23,3.53个。以TR4和TR9两个基因型为试材,进一步改进培养基和培养方法,采用NLN培养基中添加激素和活性炭方法,可大大提高产胚率,产胚量分别达到7.11和10.05个/蕾;接种后,小孢子经33℃高温预处理可显著影响产胚量。子叶形小孢子胚在光下适当培养后转入B5 BA 0.2 mg/L NAA 0.02 mg/L继代培养基上,大多数胚能长成绿芽,B5 6-BA 0.2 mg/L 3%蔗糖 1%琼脂培养基有利于小孢子胚长成植株。     

提高甘蓝型油菜小孢子胚状体成苗率的某些培养因素研究

甘蓝型油菜小孢子胚转到固体培养基上可直接发芽成苗或继代1～2次后成苗。直接成苗率与基因型、培养基成分和培养温度有关,与胚状体放置方式无关。(保604×Topas)F_2较DH保604直接成苗率高;1/2MS 0.1mg/L 6-BA较B_5 0.1mg/LGA_3利于胚状体直接发芽。胚状体转到固体培养基上经10℃低温培养5天或10天可提高直接成苗率,且10天效果更好。     

唐菖蒲体细胞胚的诱导及植株再生

以唐菖蒲球茎芽切片为外植体,经体细胞胚发生途径,进行胚性愈伤组织诱导、胚状体的诱导、胚状体发育过程及植株再生的研究。胚状体诱导培养基为MS＋2,4-D1.0mg/L＋TDZ0.2mg/L,诱导率为68.3%;将产生的胚状体首先接种于MS培养基使其充分发育,之后转入MS＋6-BA2.0mg/L培养基中诱导发芽,在转入MS培养基中使其形成完整植株。采用石蜡切片法和临时压片法对胚状体的发育过程进行了观察发现,首先外植体表层薄壁细胞经脱分化恢复分生能力,形成愈伤组织,随后在愈伤组织表面形成许多瘤状突起即胚性细胞团,胚性细胞团继续发育成球形胚、盾形胚,最后发育成熟形成完整植株。     

分葱对黄瓜、萝卜和白菜的化感作用

以黄瓜（Cucumis sativus L.）,萝卜（Raphanus sativus L.）和白菜（Brassica chinensis L.）3种蔬菜作物为受体,通过种子萌发试验及幼苗生长试验,对分葱（Allium fistulosum L.var.caespitosum Makino）根系及其地上部水浸液的化感作用进行了初步研究。结果表明：分葱根系和地上部水浸液对黄瓜、萝卜和白菜具有一定的化感作用。对黄瓜和萝卜的萌发有一定的抑制作用,而对其幼苗生长有一定的促进作用;对白菜的萌发表现为低浓度促进高浓度抑制,而对其幼苗生长有一定的抑制作用。因此,在蔬菜栽培制度中,分葱可与黄瓜和萝卜进行合理的轮作与间套作;但可能不适宜与白菜进行轮作或间套作。     

新铁炮百合种子萌发的研究

本文对新铁炮百合进行了种子发芽的研究试验,试验采用PEG引发处理和低温浸润的方式.结果表明：新铁炮百合种子通过PEG引发处理来提高其发芽能力.同时,新铁炮百合种子还可以通过低温浸润处理来提高其发芽能力.经过低温处理后的种子,发芽率随着冷藏天数的增加而增加,还可以增加种子发芽的整齐性.     

Partial incompatibility in crosses between Hordeum vulgare L. and H. bulbosum L.

Summary Certain cultivars of Hordeum vulgare L. gave low seed set (average <30%) after pollination with H. bulbosum, while others consistently gave high seed set (average >80%). The reduced seed setting occurred in crosses with cultivars which had H. distichum var. laevigatum in their ancestry. The results show that the reduced setting is probably controlled by a single dominant gene. This finding is of particular importance to breeders concerned with the use of Vada or some of its high yielding derivatives for producing haploids by interspecific hybridization.     

Breaking breeding barriers in Lycopersicon. 4. Breakdown of unilateral incompatibility between L. peruvianum (L.) Mill. and L. esculentum Mill.

Summary A brief survey is given of the occurrence of unilateral incompatibility between populations. It is reported how the unilateral incompatibility between L. peruvianum and L. esculentum has been broken stepwise by inbreeding with the aid of self-compatibility in L. peruvianum and selection in this self-compatible L. peruvianum material of absence of L. esculentum pollen tube inhibition, and how L. peruvianum material has been developed on which large-scale L. peruvianum x L. esculentum hybrid production is possible. It is concluded that the unilateral incompatibility between L. esculentum and L. peruvianum consists of a complex of separate processes.     

Genotype-environment interaction for seed yield and ODAP concentration of Lathyrus sativus L. and L. cicera L. in Mediterranean-type environments

In 1994, 407 L. sativus and 96 L. cicera lines were evaluated for phenology, seed yield and seed ODAP (a neurotoxin) concentration in the Mediterranean-type climate of south-western Australia. A selected number of lines from this study were grown at three sites in south-western Australia in 1995 and 1996, to examine genotype-environment interactions on seed yield and ODAP concentration in the seed of the two Lathyrus spp. Principal components analysis showed that L. sativus lines grown in 1995 and 1996 could be divided into two geographical origins: Indian sub-continent and Mediterranean/European. Those lines of Mediterranean/European origin were consistently higher yielding (both in 1994 and 1995/96), with much larger seeds and later phenology. In L. cicera seed yield was closely associated with greater mean seed weight and to a lesser extent with early phenology. The genotype-environment study indicated that higher yielding lines of both species generally responded to favourable environments; in the case of L. sativus the Mediterranean/European lines and for L. cicera the larger seeded, earlier phenology lines. For both species, genotype was the most important determinant of ODAP concentration and environment had less influence. Genotype-environment interactions had no effect on seed ODAP concentrations. In terms of seed yield, both species showed substantial potential in the environments tested. Further improvements in adaptation, seed yield and reduction in ODAP are possible in both species. This revised version was published online in August 2006 with corrections to the Cover Date.     

Attempts to overcome partial incompatibility between Hordeum vulgare L. and H. bulbosum L.

Summary Partial incompatibility has already been reported between Hordeum vulgare and H. bulbosum during the course of doubled haploid production, and in this paper attempts to overcome the breeding barrier are described. The methods which seem to offer most success are those of environmental adjustments and the adoption of new genotypes of H. bulbosum. Further cultivars of H. vulgare exhibiting this phenomenon are also noted.     

陆地棉×辣根棉后代主要性状的遗传变异

对陆地棉×辣根棉后代主要性状的遗传变异及回交效应进行研究 ,结果表明 :该组合杂种利用陆地棉回交三次 ,育性恢复正常 ;可育后代性状遗传变异丰富。随着回交世代增加 ,产量及其构成因素不断得到改良 ,单铃重的增加是主要的 ,其次是单株结铃数和衣分提高。并从分离世代中获得部分绒长在 31 mm左右 ,比强在 2 5～ 2 7c N· tex- 1之间 ,以及被红铃虫为害的子害率在 5 %以下的材料。     

Hybridization of Sinapis alba L. and Brassica napus L. via Embryo Rescue

Embryo rescue techniques were used to obtain hybrids between Sinapis alba L. (white mustard) and Brassica napus L. (oilseed rape) with the goal of improving the disease tolerance of oilseed rape. Hybrid plants with 31 or 43 chromosomes were only recovered, when S. alba, was used as the female parent. One hybrid was obtained from the cross S. alba L. cv. ‘Kirby’×B. napus L. cv. ‘Topas’, while 26 hybrids were obtained, when various S. alba L. cultivars were pollinated with the rapid cycling B. napus line CrGC 5006. All F₁, hybrid plants were male sterile; however, the first generation backcross to B. napus L., also obtained by embryo rescue, produced plants with 50 chromosomes and 61–84 % pollen viability. Second backcross generation seed was produced by normal sexual crossing. Preliminary cytological analyses of pollen mother cells of hybrid plants suggests the possibility of genetic exchange between the two species.     

Inheritance of groat protein percentage in Avena sativa L. × A. Fatua L. Crosses

Summary Gene action and heritability of groat protein percentage were determined in F₁, F₂, and F₃ generations of nine crosses between three Avena sativa L. cultivars and three A. fatua L. selections. Relationships among groat protein percentage, grain yield, and 100-seed weight also were evaluated. The three A. sativa parents were Dal (high grain yield and intermediate groat protein percentage), Goodland (low grain yield and high groat protein percentage), and Stout (high grain yield and low groat protein percentage). The three A. fatua parents were chosen for the study on the basis of vigorous plant growth and high groat protein percentage. The study was conducted at Madison, Wisconsin in 1979 and 1980.There was partial dominance towards low groat protein percentage. Narrow sense heritability estimates for groat protein percentage were low in Dal and Goodland crosses and intermediate in Stout crosses. In the F₂ generation, groat protein percentage was significantly higher in shattering than in nonshattering plants in 1979, but not in 1980. There were significant, positive correlations between groat protein percentage, 100-seed weight, and grain yield in F₁ and F₂ generations, but they were not large numerically. Relationships among these traits were either negative or nonsignificant in the F₃ generation. Although our results indicated that selection for higher groat protein percentage is possible when a low protein A. sativa cultivar is used, most of our simple cross progenies from A. sativa x A. fatua crosses had weak straw and were susceptible to crown rust (Puccinia coronata Cda. var. avenae Fraser and Led.).     

Allelopathic Effect of Eucalyptus globulus Labill. on Cyperus rotundus L. and Cynodon dactylon L. Pers.

The allelopathic potential of Eucalyptus globulus Labill. (gum tree) fresh and dried leaf leachates was studied using two perennial weeds, viz. purple nutsedge (Cyperus rotundus L.) and bermuda grass (Cynodon dactylon L. Pers) as test weeds. Aqueous leachate of fresh leaves of eucalyptus significantly suppressed the establishment of vegetative propagules and early seedling growth of the weeds. Leachate of fresh leaf cuttings had growth inhibitory effect on bermuda grass but showed growth promotion effect on purple nutsedge. Similarly the leachate of dried leaves of eucalyptus had differential influence on the growth of the two weeds. There is a possibility to harness the allelochemicals of eucalyptus leaves as herbicides for the management of these perennial weeds.