玉米细胞质雄性不育及其育性恢复基因的研究进展

玉米是杂种优势利用最成功的作物之一,采用细胞质雄性不育(CMS)进行玉米杂交种生产已成为杂种优势利用的有力工具。CMS是由于细胞质和细胞核的基因表达产物的不协调而产生的不育性,可被核基因组中的恢复基因恢复。根据育性恢复专效性,玉米CMS材料主要分为T、C和S三种类型。综述了这三种类型不育及其恢复基因的研究进展,分析了在不育化制种中的应用情况。     

木豆CMS杂交种资源农艺性状及品质性状分析

对自ICR ISAT成套引进最新培育成功的早、中熟组木豆CMS杂交种各6份,进行了农艺性状及品质性状分析。结果表明:(1)早熟组的成株率高,育性恢复好;其中ICPH2363的成株率、单株荚数、百粒重等性状均表现较好。(2)中熟组中有2份杂交种在成株率、株高、分枝数等性状上远超对照品种;特别是ICPH3381的分枝数极显著多于对照品种。(3)早熟组杂交种的粗蛋白、无氮浸出物等指标普遍高于对照品种;特别是ICPH2364各品质性状指标均较高,干子粒平均单产也高于对照,作为精饲料、配合饲料开发利用潜力较大。木豆CMS杂交种资源农艺性状令人满意,在我国亚热带省区应具有较好的推广利用价值。     

普通小麦不同优势杂交种及其亲本苗期根系基因的差异表达

为探讨小麦 (TriticumaestivumL .)杂种优势形成的分子机理 ,选用普通小麦品种 (系 ) 3338、6 5 5 4和 2 410TD及其强优势杂种A(3338× 6 6 5 4)和无优势杂种B(2 410TD× 6 5 5 4) ,采用mRNA差异显示技术 ,对生长至三叶一心的根系 (初生根 )基因表达差异进行了比较研究。结果发现 ,小麦杂种一代苗期根系基因表达较亲本明显不同 ,表现为数量水平和质量水平上的差异 ,且差异表达基因的数目远高于我们以苗期叶片为材料的研究结果 ,表明小麦杂交种与其亲本间的基因差异表达与所研究的组织和器官有关。比较分析发现 ,在强优势杂种组合A中 ,超亲表达和偏高亲表达基因所占比例均明显高于无优势杂种组合B。以家族特异基因替代随机引物进行的差异显示结果表明 ,MADS_box家族基因在小麦杂交种和亲本苗期根系中存在着显著的表达差异 ,且差异表达类型以杂种特异表达和亲本基因在杂种一代沉默为主 ,说明MADS_box家族基因可能与小麦的杂种优势形成具有重要关系。对杂种和亲本基因表达差异与杂种优势的关系进行了分析和讨论     

甘蓝型油菜秦优10号杂交种纯度鉴定的SSR引物筛选

为了建立一套快速可靠的油菜杂交种纯度的鉴定方法,本文以秦优10号及其亲本、杂种ZZH2为试验材料,对前人开发的2对SSR引物(7号引物, 9号引物)进行了再次筛选.结果显示,7号引物不但能很好地区别出混入杂交种中的亲本,还能将杂交种子的同母异父组合种子从杂交种中分离出来,能够用于鉴别秦优10号杂交种子的真伪;9号引物能区分出杂交种和母本,但不能区分开杂交种和父本.同时,本试验利用人工制成的秦优10号杂交种标准样(纯度为100%)以及7份大田鉴定不同纯度梯度的杂交种子对7号引物鉴定结果的准确性进行了验证,鉴定结果与大田鉴定结果基本一致.本文结果将为鉴定秦优10号杂交种纯度提供更准确的技术资料.     

花发育阶段以及温度对不同品种甜樱桃柱头可授性的影响

以‘布鲁克斯’、‘美早’、‘红蜜’等5个甜樱桃(Prunus avium)品种为试材,检测不同品种甜樱桃花期不同发育阶段的柱头可授性;并利用人工气候箱模拟花期低温(2 ℃/10 ℃)、常温(6 ℃/18 ℃)、高温(12 ℃/24 ℃)以及超高温(12 ℃/24 ℃/30 ℃)环境,研究不同温度处理对甜樱桃柱头可授性的影响。结果表明：(1)‘美早’、‘先锋’和‘萨米脱’适宜的授粉温度是常温(6 ℃/18 ℃)环境,‘红蜜’适宜的授粉温度是高温(12 ℃/24 ℃)环境,‘布鲁克斯’适宜授粉的温度范围更广,在常温(6 ℃/18 ℃)和高温(12 ℃/24 ℃)环境条件下其柱头均具有较高的活性。(2)‘红蜜’柱头对花期低温(2 ℃/10 ℃)和超高温(12 ℃/24 ℃/30 ℃)的抗性较强;‘布鲁克斯’和‘萨米脱’柱头对花期超高温(12 ℃/24 ℃/30 ℃)抗性较差;‘美早’柱头对花期低温(6 ℃/10 ℃)的抗性较强,但对花期高温(12 ℃/24 ℃)的抗性较差;‘先锋’柱头对花期低温(6 ℃/10 ℃)和超高温(12 ℃/24 ℃/30 ℃)均无明显抗性。研究认为,低温(2 ℃/10 ℃)对甜樱桃柱头可授性的影响主要在开花之后,而超高温(12 ℃/24 ℃/30 ℃)对整个开花过程柱头可授性的影响都很大。     

利用SSR标记鉴定西瓜杂交种纯度的研究

以2个西瓜杂交品种(系)的种子黑公子和04-17及其亲本为材料,用SSR标记技术研究杂种与其双亲之间的扩增谱带多态性,以甄别真假杂种.结果发现,所试验的52对SSR引物中有13对引物分别在2个西瓜杂交种和其双亲之间存在扩增条带的多态性,表现为:多数SSR引物对自交系的扩增只出现1条带,但部分引物在某些自交系中扩增出2条带,杂交种条带均为父母本的互补型,很适合做杂交种纯度鉴定.用引物CMCT134b对黑公子和引物CMGA165对04-17进行了各100粒单种子SSR鉴定,所测纯度分别为96%和100%,与田间纯度95.6%和99.7%非常接近,表明SSR标记技术在西瓜杂交种子纯度室内快速检测中的应用前景.     

青藏高原东缘同域分布的2种橐吾属杂草的合子前生殖隔离

生殖隔离是阻止种间杂交、保持物种完整性和独立性的关键,对生物多样性的产生和维持有重要意义.不同物种间的生殖隔离形成阶段、方式和强度不完全相同,因而对物种间隔离机制的研究有助于揭示物种形成和维持机制.对青藏高原东缘同域分布的2种橐吾属杂草黄帚橐吾和箭叶橐吾的花期物候观察、访花昆虫观察及花粉-柱头亲和性进行研究,分析了2种橐吾多种合子前生殖隔离机制的特点及其在生殖隔离中的作用.结果表明: 黄帚橐吾种群花期比箭叶橐吾早20 d左右,虽然盛花期存在差异,但是2种群花期存在10 d左右的重叠期,并且在重叠期内2种橐吾花粉和柱头均具有活性.2种橐吾共享传粉昆虫,为泛化传粉模式,并且传粉者对2种植物的访花行为相似,存在2种植物间交叉访问.尽管2种橐吾花期不存在完全的时间隔离,也不存在完全的传粉者隔离,但2种橐吾柱头对异源花粉的亲和性差,表现为柱头对异源花粉有明显的排斥反应,异源花粉管在柱头上的生长过程明显受阻.这种花粉-柱头排异形式很有可能是2种橐吾属植物重要的合子前隔离机制,从而避免了种间的自然杂交,更好地维持了自然种群的多样性和遗传结构的稳定性.     

‘川早枇杷’头花柱头可授性及花粉活力与花粉管生长的研究

为揭示特早熟枇杷新品系‘川早枇杷’头花坐果率低的原因,该试验采用田间调查方法观察了‘川早枇杷’头花的开花期,并用联苯胺-过氧化氢法检验了柱头可授性、TTC法测定了花粉活力、苯胺蓝染色法观察了花粉管生长情况。结果显示:(1)‘川早枇杷’头花7月中旬进入初花期,7月下旬至8月上旬为盛花期,8月中旬至下旬为终花期,头花花期的果园气温最高、最低和平均分别为34.9℃、18.9℃和26.03℃。(2)开花当天及花后1~4d柱头具有可授性,且花后1d柱头可授性最强、花粉活力最高,以后花粉活力逐渐迅速降低。(3)自花授粉的花粉管在授粉后48h抵达花柱基部、96h到达胚珠,但数量极少。研究表明,‘川早枇杷’头花具有最佳可授性的时间较短,花粉活力降低迅速,花粉管能够抵达花柱基部和进入胚珠的数量极少,花期高温等诸多因素的综合作用可能是造成其头花坐果不良的重要原因。     

甘蓝型油菜(Eru CMS)与甘蓝种间杂种的同工酶和蛋白质分析

经胚抢救获得甘蓝型油菜(Brassica napus L.)(Eru CMS)与甘蓝(Brassica oleracea L.var.capitata L.)种间杂种,前期经过流式细胞仪、柱头染色体数目、花粉活力等分析获得一些真杂种。利用电泳法,对真杂种植株的3种同工酶(SOD、EST、COD)和蛋白质进行详细分析,了解了杂种与亲本的同工酶和蛋白质的特性差异。结果表明,杂种与亲本之间的同工酶和蛋白质存在较明显的差异:杂种的SOD、COD的酶带表现为偏父本甘蓝型;杂种的EST的酶带表现为偏母本油菜型;杂种的蛋白质电泳表现为不仅具有双亲的特征蛋白带,也有其自身特征蛋白带。     

几个棉花核不育抗虫杂交种(F1)的抗虫性及经济性状分析

用两个不抗虫和一个抗虫的核不育系为母本,用抗虫品系为父本,配制3个杂交组合(GA×HB、GA5×R27、GA18×HB),研究分析杂交种的抗虫性、产量性状和纤维品质.结果表明3个杂交组合均高抗棉红铃虫,GA5×R27和GA18×HB以及GA×HB分别抗、中抗棉铃虫;3个组合的产量和纤维品质均优于对照.用核不育系作母本,特别是用抗虫核不育系作母本生产抗虫杂种,比用人工去雄生产杂种种子成本低,且有较好的抗虫性和丰产性,因而在棉花生产上具有更加广阔的应用前景.     

杂交小麦制种研究现状及展望

利用杂种优势对提高小麦单产具有重要作用,杂交小麦制种是小麦种业未来发展的重要方向之一。目前,小麦在强优势杂交组合选配方面取得较大进步。由于缺乏优异高异交结实率的制种亲本资源和高产高效杂交制种体系,导致大面积制种效率低。因此,探究杂交制种技术体系进展、亲本种质资源改良和生产流程标准化等方面的研究现状,将有利于对杂交制种发展瓶颈和未来发展方向等问题的整体把握。综述杂交小麦制种技术的影响因素,并通过商业化大田杂交作物与新型杂交小麦比较,对杂交小麦快速商业化等方面提出建议,对其发展趋势进行展望。     

Hybrid wheat seed production potential using the chemical hybridizing agent SC2053

The success of hybrid wheat depends greatly on the female seed production. The objectives of this experiment were to evaluate the effects of two doses of a Chemical Hybridizing Agent (CHA) on the stigma receptivity. In a growth chamber, plants were hand emasculated or treated with a normal (D1) or an excessive dose (D2) of the CHA. Spikes were hand pollinated at different dates during the flowering period. The CHA did not affect significantly the female receptivity neither in duration nor in intensity. We pointed out that for the hybrid seed production there was an optimal period of 5 days. If pollination took place during this period, the seed set and the 1000 grain weight were the highest.     

主要作物光温敏核雄性不育基因的研究进展与应用*

光温敏核雄性不育系在不同的生态环境条件下可以实现一系两用,简化制种程序,是农作物杂交种子生产的一种重要资源。简要介绍了主要作物杂交种子生产方式,综述了水稻、小麦、玉米、谷子等作物光温敏核雄性不育系的研究进展以及在两系杂交种子生产上的应用,并探讨了光温敏核雄性不育系的应用前景。     

A new method for hybrid seed production based on cytoplasmic male sterility combined with a lethal gene and a female sterile pollenizer in Capsicum annuum L.

Summary A new improved method for hybrid seed production was successfully tested. This method is based on using a cytoplasmic male sterile line possessing a lethal gene with action that can be easily inhibited and a female sterile pollenizer. The lethal gene ensures 100% purity of the F₁ crop. The female sterile pollenizer provides a permanent abundant flowering with excess of pollen grains that leads to increased hybrid seed production without additional labour expenses. The described scheme is applicable for other crops as well.     

Effects of ascochyta blight (Mycosphaerella pinodes Berk. & Blox.) on biomass production, seed number and seed weight of dried-pea (Pisum sativum L.) as affected by plant growth stage and disease intensity

The effects of ascochyta blight due to Mycosphaerella pinodes on biomass production, seed number and seed weight according to physiological stage and disease intensity were examined. Pea plants were grown in a glasshouse and inoculated with various concentrations of conidia before flowering, at flowering of the second fructifer node (FLO2), at the start of seed filling of the first fructifer node (FSSA1) or the second fructifer node (FSSA2). Uninoculated plants were used as controls. Whatever the stage of inoculation (FLO2 or FSSA2), the disease reduced plant growth and the decrease depended on disease intensity on foliar organs. The seed number was reduced for plants inoculated before flowering, at FLO2 and at FSSA1 and the reduction was linked to disease intensity on foliar organs. At each node, seed number was reduced if the disease occurred before FSSA of the node. The mean seed weight per plant was decreased in plants inoculated at FSSA1 and FSSA2 and the higher the disease intensity on aerials organs, the greater was the reduction of the seed weight. For individual nodes, only inoculations after the beginning of seed filling had a negative effect on mean seed weight at harvest. We found that the decrease of seed number induced by the disease was proportional to aerial biomass production before the end of the period of seed production.     

Use of functional male sterility in seed production of tomato hybrids

The aim of our research is the elaboration of a simple method of tomato hybrid seed production at the development of hybrids F₁ (common and parthenocarpic) on the basis of functional male sterility for ecological conditions of Belarus. The results of study of tomato flowering biology are discussed. The optimal term for pollination without emasculation of functional male sterile forms Z-313 and B-3-1-8 is the 3-6-th days and parthenocarpic functional male sterile forms B-2-2, B-2-5, B-2-6, ą-3, ą-4, Z-1-3 — the 2-4-th days after the phase of yellow-green bud. Forms with short pistil (C-9464, C-3-1, ą-2) may be used in hybrid seed production after the removal of filaments directly before pollination. The existence of a marker gene (potato leaf) gives a good possibility to reject non-hybrid seedlings.     

CRISPR/Cas9‐mediated knockout of Ms1 enables the rapid generation of male‐sterile hexaploid wheat lines for use in hybrid seed production

The development and adoption of hybrid seed technology have led to dramatic increases in agricultural productivity. However, it has been a challenge to develop a commercially viable platform for the production of hybrid wheat (Triticum aestivum) seed due to wheat's strong inbreeding habit. Recently, a novel platform for commercial hybrid seed production was described. This hybridization platform utilizes nuclear male sterility to force outcrossing and has been applied to maize and rice. With the recent molecular identification of the wheat male fertility gene Ms1, it is now possible to extend the use of this novel hybridization platform to wheat. In this report, we used the CRISPR/Cas9 system to generate heritable, targeted mutations in Ms1. The introduction of biallelic frameshift mutations into Ms1 resulted in complete male sterility in wheat cultivars Fielder and Gladius, and several of the selected male‐sterile lines were potentially non‐transgenic. Our study demonstrates the utility of the CRISPR/Cas9 system for the rapid generation of male sterility in commercial wheat cultivars. This represents an important step towards capturing heterosis to improve wheat yields, through the production and use of hybrid seed on an industrial scale.     

State of the reproductive system of populations of species of the genus Glycyrrhiza L. (Fabaceae)

Reproductive features of the valuable medicinal herbs Glycyrrhiza glabra L., G. uralensis Fisch., and G. korshinskyi Grig. were investigated; an assessment was made of the state of the reproductive systems of populations located under introduction conditions in the Central Urals and in the zone contact of the species ranges in the southern cis-Urals. The states of the male and female reproductive systems, seed productivity elements, pollination features, and the viability of seeds produced by different pollination treatments were studied. For the three Glycyrrhiza species, the seed productivity indices were found to decrease considerably starting from the early stages of development of the female reproductive system and continuing to seed maturity. A quantitative analysis of seed productivity elements taking into account the flowering duration of the species showed that the seed production system of the species is very efficient; even in the introduced populations located north of the range, it is able to produce viable seeds in years with favorable growing conditions. Qualitative and quantitative indices of the reproductive system were used to characterize samples from the zone of contact between the ranges. Embryological analysis confirmed the possibility of interspecific hybridization and the prevalence of hybrid forms among the samples. A broad distribution of interspecific hybridization in Glycyrrhiza in various parts of the ranges is assumed. Glycyrrhiza species are characterized by seed and vegetative reproduction. Vegetative reproduction is limited in space but efficiently ensures reproduction of individuals and formation of vegetative clones. Seed reproduction is characterized by indices such as amphimictic seed formation, strict entomophily, and interspecific compatibility. Seed reproduction is a factor that controls the possibility of wide propagation of the genetic material in space and, hence, the formation of mixed and hybrid populations leading to a higher intraspecific and interspecific diversity of the genus.     

Male sterility systems in wheat and opportunities for hybrid wheat development

The common wheat (Triticum aestivum L.) is a poly(hexa)ploid, derived from an amphi-diploidization process involving the donor species—Triticum urartu, Aegilops speltoides, Triticum turgidum, and Aegilops tauschii. The genetic diversity of the autogamous wheat is narrow, which is a major reason for lesser rate of yield gain in wheat, in contrast to rice and maize. It is desirable to encourage hybrid breeding, i.e., combining different lines into genetically divergent heterotic pools. Thus, hybrid plants are a unique combination of desired alleles produced by crossing between genetically different parental lines. Hybrid seed production in a crop requires male-sterile female parents along with a reliable outcrossing system. The male-sterile female parent prevents pollen shedding and self-fertilization, maintaining the purity of hybrid seeds. An outcrossing system enhances hybrid seed production. This article emphasizes the biological relevance of crossbreeding and self-pollination in wheat, and reviews different male sterility systems which could be utilized for the development of hybrid wheat. Several biotechnological approaches and their practical utility in generating cross-compatible male-sterile female parent lines have been discussed.     

Male Sterility in Tomato

Male sterility research has been directed toward two goals: identifying genes required for the pollen development pathway and, more practically, identifying genetically stable lines that can be used in hybrid seed-breeding programs. The present resurgence of interest in male sterility remains true to these goals, but in addition seeks a molecular understanding of pollen development in order to genetically engineer controllable male sterility for hybrid seed production. In this review, we discuss the genetic and histochemical studies of tomato male sterile mutants that were conducted prior to 1970 in the context of gene expression and interaction. We also examine the use of molecular biological techniques in recent studies of male sterility and report on the current strategies being used for hybrid seed production.