小麦与玉米杂交及单倍体的产生

应用普通小麦不同品种（品系）与苏玉４号杂交,喷洒１１０ｐｐｍ的２,４－Ｄ一至二次,授粉后子房膨大,其膨大率因品种不同而异。在部分膨大子房中剥取到发育幼胚,经组织培养后,获得单倍体小植株,植株未结实。     

小麦与玉米杂交产生小麦单倍体的研究进展

在作物改良中,常利用植物属间的远缘杂交,将异种植物的有用性状向栽培种转移。植物远缘杂交的难易程度一般由两亲本亲缘关系的远近所决定。近年来的研究表明,禾本科中的两个亚科即早熟禾亚科（Ｐｏｏｉｄｅａ）和黍亚科（Ｐａｎｉｃｏｉｄｅａ）之间的杂交并不完全受这一规律的限制,特别是六倍体的普通小麦（早熟禾亚科）和玉米（黍亚科）之间的杂交,可以发生高频率的受精作用和胚胎形成。为了扩大小麦的基因资源,近年来育种学家突破了小麦族内各物种间的杂交限制,观察到小麦×玉米和小麦×高粱的受精率（单、双受精）分别可达到５９…     

玉米花粉诱导普通小麦产生单倍体技术介绍

采用玉米花粉诱导普通小麦产生的单倍体幼胚,经离体培养一个世代即可获得纯系。在陕西杨凌地区,1月27日-2月7日室内分期点播多类型玉米,3月1日移栽入大棚中,从4月中旬开始便可获得持续的多类型玉米花粉。小麦散粉前3-5d授粉,12h和36h后用250mg·L^-1 2,4-D处理后的得胚率最高（18．2％）。用1／2MS＋0．2mg·L^-1 IAA＋0．2mg·L^-1 6-BAP＋2％蔗糖＋7．5g·L^-1琼脂培养基进行幼胚离体培养的效果最好,平均幼苗产生率为92．15％。授粉100朵小花可以获得大约16个单倍体幼苗。     

不同倍性小麦和玉米不同群体杂交诱导小麦单倍体的研究

自从Ｚｅｎｋｔｅｌｅｒ等［１］首先报道了小麦×玉米受精现象以来,许多学者对六倍体普通小麦与玉米杂交进行了广泛的研究,获得单倍体的普通小麦,并筛选到一些杂交亲和性较高的亲本材料［２］。但四倍体小麦与玉米杂交研究报道较少。ＯＤｏｎｏｕｇｈｕｅ等用四倍体小麦与玉米杂交获得单倍体胚［３］。随后,Ａｍｒａｎｉ等［４］和孙敬三等［５］利用这一方法相继获得四倍体小麦的单倍体苗。本文报道了不同倍性的小麦基因型与玉米不同群体杂交对诱导小麦单倍体的影响１　材料和方法１．１　亲本材料用作母本的二倍体小麦有一粒小麦（…     

不同处理对小麦×玉米产生小麦单倍体胚频率的影响

在田间条件下,选用3个小麦材料与不同玉米品种进行杂交,用含不同体积分数二甲基亚砜(DMSO)的100 mg/L 2,4-D溶液和3%DMSO与2,4-D配比处理两种方法诱导小麦×玉米产生单倍体.结果表明,在不同DMSO处理中,2%体积分数的DMSO最佳处理平均得胚率最高为15.8%,3%处理最低(7.1%),二者差异显著;在激素配比试验中,以授粉后48 h采用小花滴注100 mg/L 2,4-D溶液、授粉后72 h再次采用小花滴注并穗下茎节注射3%DMSO的100 mg/L 2,4-D溶液的处理得胚率最高(14.1%),但与3%DMSO的2,4-D 1次处理(13.4%)2、,4-D 1次处理(12.7%)、2,4-D 2次处理(10.6%)和3%DMSO的2,4-D 2次处理(12.6%)之间无显著差异,而这5种处理的得胚率均与对照和未授粉只进行3%DMSO的2,4-D 1次处理存在极显著差异.     

不同处理对小麦×玉米产生小麦单倍体胚频率的影响

在田间条件下,选用3个小麦材料与不同玉米品种进行杂交,用含不同体积分数二甲基亚砜（DMSO）的100 mg/L 2,4-D溶液和3%DMSO与2,4-D配比处理两种方法诱导小麦×玉米产生单倍体.结果表明,在不同DMSO处理中,2%体积分数的DMSO最佳处理平均得胚率最高为15.8%,3%处理最低（7.1%）,二者差异显著;在激素配比试验中,以授粉后48 h采用小花滴注100 mg/L 2,4-D溶液、授粉后72 h再次采用小花滴注并穗下茎节注射3%DMSO的100 mg/L 2,4-D溶液的处理得胚率最高（14.1%）,但与3%DMSO的2,4-D 1次处理（13.4%）2、,4-D 1次处理（12.7%）、2,4-D 2次处理（10.6%）和3%DMSO的2,4-D 2次处理（12.6%）之间无显著差异,而这5种处理的得胚率均与对照和未授粉只进行3%DMSO的2,4-D 1次处理存在极显著差异.     

单倍体小麦与羊草的属间体细胞杂交

以失去植株再生能力的小麦单倍体愈伤组织和羊草二倍体愈伤组织为材料,游离原生质体,并用紫外线自理２羊草原生质体,用ＰＥＧ法融合,对融合克隆进行染色体和同工酶分析,在已贩２６个克隆中有２１个是杂种,其中有一个克隆再生出短命小植株,结果 体小麦与二倍体草的不对称融合虽然再生互补效应不如二倍体小麦,然而杂种优先生长的现象仍然比较明显。如果改善实验条件和双亲原始的再生能力,这种融合方式仍然可以利用。     

由小麦＊玉米获得的普通小麦加倍单倍体后代的RFLP变异

用小麦（ＴｒｉｔｉｃｕｍａｅｓｔｉｖｕｍＬ．）的ｒＤＮＡ克隆ｐＴａ７１和与小麦基因组有部分同源性的玉米（ＺｅａｍａｙｓＬ．）ＤＮＡ克隆作探针,对由小麦＊玉米获得的普通小麦加倍单倍体后工群体进行ＲＦＬＰ分析。     

小麦×玉米单倍体植株再生体系的建立

为获得一定规模的小麦单倍体植株以构建小麦DH(Double Haploid)群体,采用小麦(Triticum aestivum,2n=42)与玉米(Zeamays,2n=20)远缘杂交诱导小麦单倍体胚,经胚拯救产生单倍体植株,研究了1/2MS培养基中幼胚取材时期、幼胚大小、4℃处理时间、暗处理时间对单倍体胚培养再生成苗的影响,结果表明:授粉后12天~16天取材的幼胚经胚拯救后成苗率无明显差异;0.5mm~1.0mm大小的幼胚成苗率显著高于0mm~0.5mm和1.0mm~1.5mm大小的幼胚成苗率;1天~3天短期4℃处理对胚萌发具有一定促进作用,但处理3天后,出愈率和成苗率降低;胚培养过程中12天左右的24h暗处理能有效提高成苗率。     

The Production of Haploid Wheat Plants via Wheat X Maize Hybridization

The intergeneric cross between wheat and maize are characterized by a high frequency of formation of hybrid embryos, but maize chromosomes are rapidly eliminated in the first few cell division cycles to produce haploid wheat embryos. If left the embryos on the plants they will soon abort, as a result of the absence or poor development of the endosperm. Embryo rescue techniques should not enable these embryos to grow to plants because of the embryos were extremely young for embryo culture. Viable embryos were obtained at much higher frequenc, if spikes containing cross-pollinated florets were dipped in 100 ppm 2,4-D solution 4 hours after pollination. Of the 382 florets treated, 64(16.8%) embryos were obtained 10 days after treatment, and 47 plants recovered on the culture medium. In control (2,4-D not applied) only 1 (0.96%) embryo and 1 plant was obtained from 104 florets. This simplified technique should enable haploid wheat plants production through wheat - maize to apply to practical breeding.     

Diploid Hybridization in a Heterothallic Haploid Yeast, Saccharomyces rouxii

By crossing of a heterothallic haploid yeast, Saccharomyces rouxii, we have succeeded in obtaining diploid hybrids. This paper shows one possible method of breeding heterothallic haploid yeasts for industrial application. S. rouxii is highly salt-tolerant and plays an important role in shoyu and miso fermentation. Therefore, genetic improvements of the properties are of commercial importance. Since newly isolated S. rouxii could neither conjugate nor sporulate on sporulation media commonly used, a suitable medium for conjugation and sporulation of S. rouxii was firstly investigated. A 5% NaCl Shoyu-koji extract agar was found to be most efficient. Next, we tried to get diploid strains by mass culture of two mating types on the conjugation medium, but several phenomena made this difficult: (i) zygotes quickly sporulated before budding; (ii) several zygotes showed terminal budding, but the buds could not grow into diploid cells, suggesting they would be heterocaryon; and (iii) a few zygotes lost their viability. After trying to isolate and cultivate a large number of zygotes in various combinations of crossing by micromanipulation, we fortunately recognized that large cells arose from some combinations. The analysis of ploidy suggested that the large cells would be diploid. Also, they showed sporulation of typical Saccharomyces, i.e., two to four spores in an unconjugated ascus. The diploid strains thus obtained were highly salt-tolerant and stable in liquid medium. Therefore, the procedure presented here would be effective for breeding salt-tolerant S. rouxii.     

菊科植物单倍体研究进展

单倍体培养是快速获得菊科纯合系的重要途径。目前已进行单倍体研究的菊科植物共有13个种,其中9个已成功获得单倍体植株。菊科中诱导单倍体的途径有花药培养、小孢子培养、离体雌核培养、远源杂交和辐射花粉诱导单倍体。本文详细论述了不同外植体发育时期、预处理、培养基、培养条件等因素对单倍体植株诱导再生的影响。对菊科植物单倍体诱导的几种途径进行对比总结,指出研究中存在的问题并提出思路和建议。     

小麦与谷子不对称体细胞杂交

以不同剂量的紫外线(UV)照射谷子(Setariaitalica cy. Shanxi)原生质体为供体与普通小麦(Triticum aestivum)济南177和99P的原生质体用PEG法诱导融合.利用同工酶,RAPD和染色体分析再生的克隆及白化苗.从小麦济南177与谷子融合再生的86个克隆中,24个被鉴定为杂种克隆;而小麦99P与谷子融合再生的67个克隆中,27个被鉴定为杂种克隆.虽然用作融合材料的双亲培养细胞均丧失再生能力,但是部分来源于低剂量UV处理的杂种克隆再生了绿点、根和白化苗.证明小麦体细胞杂交中的双亲再生能力互补现象也存在于远缘族间融合组合中.讨论了小麦远缘族间融合未能再生绿色植株的原因.     

Haploid Wheat Induction by Crosses Between Different Ploidy Wheat and Different Populations of Maize

Haploid embryo and plant producing frequencies were studied by crossesing diploid, tetraploid and hexaploid wheat with landraces,hybrids and inbred lines of maize. It showed significant differences among the wheat and maize populations. The tetraploid and hexaploid wheat were better than the diploid. High frequencies were obtained by using tetraploid wheat of Triticum turgidum cv. TG14 and maize landraces cv. Xiaoyumi and Xiao Huangmaya. The highest haploid plant producing frequency (6.95 %) was obtained in the TG14 × Xiaoyumi.     

多花黑麦草与普通小麦的杂交

多花黑麦草二倍体种,具有14条染色体。用普通小麦与多花黑麦草杂交,获得了杂种,杂交结实率为0.058%。杂种F1表现为畸形,其体细胞染色体数为28,F1植株产生的花粉败育,雌蕊不孕,用普通小麦和多花黑麦草回交均未获得回交种子,有待于用秋水仙素加倍染色体以获得异源四倍体。     

The Effects of Temperature and Light Intensity on Embryo Numbers in Wheat Doubled Haploid Production through WheatxMaize Crosses

Triticum aestivumxZea mayscrosses are now widely used in theproduction of wheat doubled haploids to produce homozygous lines.Seasonal effects are known to influence the number of haploidembryos produced through wheatxmaize crosses, but the effectsof temperature and light have not been quantified. This studyinvestigated the effect of temperature and light intensity onhaploid embryo production. New Zealand wheat cultivars weregrown in a glasshouse until booting when they were transferredto growth cabinets at three temperatures (day/night; 17/12,22/17 or 27/22 °C at an irradiance of 250 µmol m^-2s^-1PAR).In another experiment, wheat lines were transferred to a growthcabinet at one of three light intensities (300, 500 or 1000µmol m^-2s^-1PAR at 22/17 °C day/night, with a photoperiodof 16 h). The temperature and light intensity at which pollinationswere made and subsequent fertilisation and embryo developmentoccurred, significantly (P<0.01) influenced the frequencyof haploid embryo production. The optimal temperature for embryorecovery was 22/17 °C. The greatest number of embryos wasproduced at a light intensity of 1000 µmol m^-2s^-1. Thesefindings will result in improvements in the overall efficiencyof the wheatxmaize system for wheat doubled haploid production.Copyright1998 Annals of Botany Company Intergeneric crossing, temperature, light intensity,Triticum aestivum,wheat,Zea mays,maize.     

混合小麦亲本与新麦草不对称体细胞杂交体系的建立

以小麦品种济南177悬浮细胞系来源的原生质体与同品系胚性愈伤组织制备的原生质体混合后作为受体;以经过380μＷ/ｃｍ²紫外线照射1min、2min的新麦草原生质体分别作为供体,用PEG法诱导融合。组合Ⅰ(176+cha9+新麦草UV 1min)获得16个再生克隆。经过形态学、同工酶、染色体和RAPD分析,确定其全部为属间体细胞杂种。其中的5个克隆再生杂种植株。用7对小麦SSR引物对杂种克隆的叶绿体基因组进行了分析;组合Ⅱ(176+cha9+新麦草UV 2min)只获得3个克隆,且逐渐褐化死亡。表明以小麦济南177的两种培养细胞混合作受体的融合体系有利于杂种的获得及再生;紫外线对融合产物的生长发育有明显的剂量效应。