三交稻杂种优势利用的初步探讨

用优良水稻不育系作母本,用大面积推广或新近培育且对不育系有全保持能力的优良水稻品种作父本(下称临时保持系),杂交产生杂种一代(下称杂种不育系),再与原不育系的恢复系制种,产生供生产上利用的杂种,称三交稻。 利用三交杂种优势在玉米和高粱中较为普遍。玉米的三交种能把三个自交系的优良性状集于一体,并且可提高制种产量,减少制种面积,获得较大的经济效益。国外推广的三交高粱,具有比三系单交种更广泛的适应性,在不良条件下具有稳定的产量,且制种产量较高。 在水稻方面,杨仁崔曾报道四汕2号《 V。;AX珍汕97) F;AXIR。4〕三交种的制…     

玉米雄性不育性研究──XⅡ利用两系法配制玉米不育杂交种

利用两系法配制玉米不育杂交种。应具备条件是：(1)不育系抗病性强；(2)所采用的不育系应归属C群；(3)不一育系应持有较多的保持系。研究指出，按照不育系双保持特性，利用掺和法配制杂交种。本文还就利用不育化单交种组配三交种、制种产量高的原因和恢复系的利用做了讨论。     

四川棉花核不育杂交种利用研究进展与前景

２０多年来，采用“两系法”配制陆地棉品种间杂交种，先后选育出“洞Ａ”、“７５１Ａ”、“４７３Ａ”、“ＭＡ”核不育系，与此同时，研究建立了与核不育相适应的良繁体系及种子生产体系。先后筛选培育出了川杂１、２、３、４、６号，内杂１号、杂交早熟系列杂交种，平均增产皮棉１７６．５５ｋｇ／ｈｍ２，累计推广面积５０万公顷。近年来，又从“洞Ａ”系中，培育成功一种核不育完全保持系即ＭＢ系，利用ＭＢ系同核不育系（ｍｃ１ｍｃ１）杂交生产一种新的不育系即ＭＡ系（ｍｃ１ｍｃ１），其后代不育株率达１００％，不育度达９５％～１００％。采用“二级法”实现了核不育“三系”配套。标志着利用核不育系配制杂交种应用于生产的又一次重大突破，将有力地推动四川杂交棉研究和应用的发展。     

杂交稻对稻瘟菌的抗性谱及亲本抗性的遗传研究

分别采用４０～５１个不同致病类型的稻瘟菌株，对８个不育系、１６个恢复系和２２个杂 交种进行单菌株接种。结果表明，供测恢复系抗谱较广，不育系抗谱狭窄。杂种Ｆ１的抗性水平 略低于抗性较高的亲本（恢复系）；亲本抗性对杂种Ｆ１的遗传８０．８３％为显性，提高不育系的抗 性水平可扩大杂种Ｆ１的抗性谱。     

水稻红莲型不育系粤泰A在杂交稻育种中的利用特性

试验初步阐明了水稻红莲型不育系粤泰Ａ在杂交稻育种中具有以下特点：（１）稳定的雄性不育性，在南京１９９４年和１９９５年的８月１５～３０日镜检其花粉可育率均低于１．５％，套袋自交结实率低于０．０８％；（２）良好的制种性状，该不育系的柱头外露率达９７％，异交结实率６１．５％±９．８％，每平方米颖花数达４２１７９个，均极显著地高于珍汕９７Ａ；（３）该不育系与中粳广亲和系配组杂种出穗期表现受积温影响较大，而受日长变化影响较小，呈现明显的感温特性。因此，可以预见该类组合在生产上具有较广泛的生态适应性。     

甘蓝型油菜优质胞质不育系492A、保持系492B的选育

农艺性状好的双低甘蓝型油菜品系２２４－２同时分别与非优质的胞质不育系Ｄ６Ａ和保持系Ｄ６Ｂ杂交,使遗传基因转育到Ｄ６Ａ、Ｄ６Ｂ之中,再从（Ｄ６Ｂ＊２２４－２）ＢＣ１Ｆ２中选株与（Ｄ６Ａ＊２２４－２）ＢＣ１Ｆ２中分离朱育株测充、回交、同时测定父本品种,。这样能较快地稳定农艺性状,并将不育基因、保持基因和优良品质基因等整合到亲不育系、新保持系中,新不育系４９２Ａ和新保持系４９２Ｂ的特征性多倾向于２２４－     

甘蓝型油菜（B.napusL.）细胞核雄性不育系杂种“中杂3号”的选育和遗传分析

以70-506花叶自交系中的天然雄性不育株为母本,先后同齐菲和加油3号杂交以改良综合经济性状。再连续用兄妹交保持和选择,育成1081AB雄性核不育“两用系”。通过不同品种测交和选育,育成恢复系1081C。在组合鉴定试验中,F1杂种比CK(甘油5号)增产30％;在湖北省油菜区试中比“中油821”增产11.45％,含油量高3.92％,成熟早3.8天。并对1081AB不育系的遗传组成作了初步分析。     

红莲型优质不育系粤泰A的选育及其主要特征特性

以红莲型不育系丛广４１Ａ作不育胞质源供体，采用杂交选育和回交转育的方法，育成了一个新的红莲型优质不育系－粤泰Ａ。该不育系具有以下特性．１．群体不育株率达１００％，不育度达９９．８６％；２．柱头外露率达９１．６％，制种产量可比珍汕９７Ａ高３８％至６２％；３．米粒细长，垩白米率仅８％，比珍汕９７Ａ减少达７８％，配制的杂种在外观品质性状上较珍汕９７Ａ组合可提高一个品质等级；４．较强的感温性，在广州作早，     

徐优3—2

徐优３—２系江苏省徐州市农科所１９８６年用中粳不育系徐８０—７Ａ为母本，江苏省农科院粮作所的宁恢３—２恢复系为父本配组育成的杂交中粳组合。１９９３年４月经江苏省农作物品种审定委员会审定通过。１产量表现１９９１～１９９２年参加江苏省杂粳区试，两年平均亩产６４５．０ｋｇ，比对照盐粳２号增产１６．２％。１９９２年江苏省杂粳生产试验平均亩产５４１．２ｋｇ，较盐优５７（ＣＫ１）增产４．７％，较汕优６３（ＣＫ２）增产０．９％，较泗稻９号（ＣＫ３）增产１５．４％。１９９１～１９９２年徐州市生产试验，两年平均亩…     

云南紫稻细胞质无花粉型三系及杂种F1的AFLP指纹图谱的构建与分析

利用AFLP分子标记对云南紫稻细胞质无花粉水稻三系及杂种F1进行了指纹图谱的构建与比较分析。从14对引物中筛选出8对具有明显多态性的引物。天香018（天香A×珞恢018)材料组（不育系、保持系、恢复系及杂种F1）共扩增出179条带,其中有52条多态性谱带,占总带数的29.05％,平均每对引物可以扩增出6.50条多态性谱带;天香806(天香A×珞恢806)材料组(不育系、保持系、恢复系及杂种F1）共扩增出177条带,其中有50条差异带,占总带数的28.25％,平均每对引物可以扩增出6.25条多态性谱带。特别明显的是在引物对E ATG/M CAC的扩增中,在AFLP指纹图谱中出现两条特征带（a带和b带）,为保持系所特有,能够明显区别于不育系、恢复系和F1。在另外一些引物对中也观察到不育系与保持系之间的差异带。     

甘蓝型油菜细胞质雄性不育三交种和单交种的优势比较

甘蓝型油菜细胞质雄性不育三交种及其相应的单交种的杂种优势研究结果表明，三交种、单交种相互之间，三交种之间及单交种之间的单株产量存在着显著差异，其他主要性状差异极显著。比较各性状平均差异，三交种单株产量略优于单交种，其他各性状则相当。１２个三交种中有２个的单株产量略高于最优的单交种。     

甘蓝型油菜细胞质雄性不育三交种优势潜力分析

甘蓝型油菜细胞质雄性不育三交种和相应单交种进行了对比,结果表明:三交种的总体平均产量略低于单交种,但两者差异不显著,产量最高的组合是单交种09×412,居第二位的是三交种09A×10B×355.与相应的两个单交种相比较,25%的三交种比其两个单交种具有较明显的优势,33.3%的三交种杂种优势介于两个单交种之间,其余41.7%的三交种优势低于两个单交种.12个三交种的各性状株间变异系数平均值除单株角果数和角粒数较明显高于单交种的平均值外,其它性状株间变异系数平均值相当.三交种的整齐性略差于相应的两个单交种,而抗倒性和抗菌核病能力强于相应的两个单交种或介于两个单交种之间.     

不同倍性栽培稻与药用野生稻种间杂交不结实性的比较胚胎学观察

以栽培稻(Oryza sativa)品种L202二倍体（L202 2x）及其同源四倍体（L202 4x）作母本分别与药用野生稻（Oryza officinalis）杂交,比较了两个杂交组合的杂交结实性及影响结实性的杂种胚胎发育细胞学。两个杂交组合所取得的一致结果是：杂交授粉后30 d所有杂交小穗均干枯死亡,不能结实;种间杂交不结实的原因在于受精和杂种胚胎胚乳发育异常。两个杂交组合的受精和杂种胚胎胚乳发育虽然均存在双受精、单受精和未受精类型,但就受精率而言,L202 2x作母本的平均总受精率为59.45％,略高于L202 4x（54.87％）; L202 4x的单受精率（24.60％）则高于L202 2x的单受精率（15.30％）。两个杂交组合的杂种胚胎胚乳发育均严重异常,虽然在授粉后1 d形成小的球形胚;到授粉后3 d,胚胎发育停滞并开始解体;至授粉后5 d,只有二倍体杂交组合的极少数胚胎可发育到梨形胚时期,四倍体组合的胚胎则基本全部解体。双受精胚囊内胚乳发育更为异常,在授粉后1 d,游离胚乳核就开始解体退化,到授粉后3 d不能形成细胞化胚乳或细胞化过程异常。与L202 2x作母本的杂交相比,以L202 4x作母本所得杂种胚胎发育更为滞后,且退化严重,形成的游离胚乳核少,解体早,不能进行细胞化。因此,利用同源四倍体栽培稻与药用野生稻杂交获得种间杂种的难度更大。     

配子鉴定法及其在油菜优良恢复系选育中的应用

利用配子鉴定法研究从恢复系间杂交后代中选育更优恢复系的可行性，可恢复系间杂交F1与不育系配制三交种的单株产量测定结果表明，三交种AF1－3即组合NA6／NR1／NR3的单株产量变幅大，优良单株频率高，单株美元产量高，提供雄配子杂交组合（NR1／NR3）的优良配子频率较高，后代中较易筛选出与不育系配合力得到改良的优良恢复系，经过连续3全节代的配合测定及选育，已从恢复系统杂交组合NR1／NR3的后代中选育出优良恢复系。     

Comparative Embryological Studies on Infertility of Interspecific Hybridizations Between Oryza sativa with Different Ploidy Levels and O. officinalis

As maternal parents, diploid (L202-2x) and autotetraploid (L202-4x) of Oryza sativa cv. L202 were crossed with O. officinalis. Embryo development and fertilization in these two crosses were comparatively studied. There were no mature hybrid seeds obtained because all the hybridized spikelets died 30 days after pollination. The main reasons for no seed set were abnormal fertilization and development of the embryos and endosperms in the interspecific hybrids. There were double- fertilization, egg cell single-fertilization and non-fertilization in these crosses. Although 59.45% and 54.87% of hybrid embryos produced in the crosses of L202-2x/O. officinalis and L202-4x/O. officinalis, respectively, hybrid embryos ceased to develop or degenerated and plenty of free endosperm nuclei were in disaggregating state without developing cellular endosperms three days after pollination. Besides, some embryological differences in these two crosses were found, that is, the rate of double-fertilization and total rate of double- and single-fertilization in L202-2x/O. officinalis were higher than those in L202-4x/O. officinalis. The embryo and endosperm of hybrids developed more slowly, and embryos and free endosperm nuclei were more severely degenerated in L202-4x/O. officinalis than in L202-2x/O. officinalis. Five days after pollination, a few of embryos in L202-2x/O. officinalis developed into pear-shaped ones, however, embryos in L202-4x/O. officinalis were all degenerated. Therefore, it is more difficult to obtain interspecific hybrids by wide crosses between autotetraploid of O. sativa and O. officinalis.     

杂交小麦杂种一代白粉病抗性表现规律的研究

为探讨杂交小麦杂种一代白粉病的抗性表现规律,以陕西不同地区小麦白粉病流行菌种做菌源,通过田间和苗期接种,对9份抗、感白粉病小麦亲本材料和9份大田感病品种及其杂交F1代进行抗病性鉴定,并结合SCAR和SSR分子标记进行了检测.结果表明:(1)以N95175、N9209为亲本的杂交F1含有Pm21基因,苗期和成株期抗病性均很好,与抗病亲本的抗病性表现基本一致,符合显性遗传,其抗病性主要由显性单基因控制.(2)以N9134、N9227A为亲本的杂交F1含有PmAS846基因,成株期抗病性较好,苗期大部分表现抗病;以N9227A为亲本的杂交F1中有40%的杂交组合表现中感,该抗性基因不完全符合单基因显性遗传,其表达在一定程度上受遗传背景及环境的影响.(3)中国春为苗期感病、成株期抗病材料,其与抗病亲本杂交F1代的抗病性接近或略高于抗病亲本;与感病品种杂交F1代的抗病性介于双亲之间.(4)白粉病遗传属于细胞核遗传,正反交F1代苗期抗病性无明显差异,杂交种的抗病性与双亲相关.因此, 在组配小麦强优势杂种组合时应尽量选用抗病的品种作为亲本之一,并考虑慢病性品种的应用.     

Insect-mediated cross-pollination in soybean [Glycine max (L.) Merrill] : I. Agronomic performance

In soybean, manual cross-pollination to produce large quantities of F₁ hybrid seed for yield trials is difficult and time-consuming. Conversely, insect-mediated cross-pollination has been shown to produce large quantities of hybrid seed in soybean and could facilitate the identification of heterotic patterns. The objective of our study was: (1) evaluate F₁ hybrid soybean plants from single crosses for yield and agronomic traits over several environments and (2) compare hybrid performance of the single crosses to lines developed from three-way crosses and backcrosses. In 2003, F₁ seed of single-crosses and their parent lines were evaluated in replicated experiments at three locations. Also in 2003, three-way crosses, and BC₁F₁ seed were produced. In 2004, three-way crosses, BC₁F₁ crosses, and their parent lines were evaluated at one location. High-parent heterosis (HPH) in single-crosses for grain yield ranged from −41.11% to +11.19%; for protein content from −4.34% to +3.53%, and for oil content from −13.22% to −0.84%. In three-way crosses, HPH for yield ranged from −25.21% to −4.50%, for protein from −2.72% to +1.92%, and for oil from −5.87% to −1.20%. For BC₁F₁ crosses, HPH for yield ranged from −15.65% to +41.97%, for protein from −2.57% to +1.69%, and for oil from −2.47% to +2.22%. Although positive heterosis levels were observed across all populations tested to determine the economic feasibility it is imperative that more tests of more cross-combinations be evaluated in replicated environments. Extensive research in different environments must be conducted to determine what parental combinations will produce the highest heterosis levels, and to develop criteria for selecting the parents with the best combining ability. This will be important to maximize agronomic performance that can economically justify the use of hybrids in soybean production.     

杂交早稻亲本遗传差异及其与杂种优势的关系

以４个不育系、７个恢复系及其配制的２８个杂交早稻组合为材料,根据８个农艺性状进行主成分和聚类分析,研究了杂交早稻亲本间的遗传差异状况及其与杂种优势的关系。结果表明,１１个亲本间的平均遗传距离为５．９２６８,最大为１９．２５２７,最小为０．３４８９;不育系内和恢复系内各亲本之间存在一定的遗传差异,且保持系内的遗传差异显著大于恢复系内的遗传差异,但两者与保持系与恢复系间的遗传差异没有明显的不同。相关分析表明,亲本间的遗传距离与杂种优势及杂种产量关系不密切。     

不结球白菜胞质雄性不育三交种选育研究及配合力分析

为了利用不结球白菜临保不育系来克服微量花粉的问题及构建三交种,进行了不结球白菜不育系育性的鉴定、品比试验及配合力分析.结果表明:临保不育系的不育性更加彻底;在株高、叶长、叶宽、叶柄长、叶柄宽和叶数等6个农艺性状中,三交种叶宽与单交种差异达极显著水平,其它性状差异均未达显著水平;在叶片重、叶柄重、短缩茎重和单株重等4个产量性状中,三交种叶柄重与单交种、对照种差异达显著水平,其它性状差异均达极显著水平;临保不育系CMS1103A×1105B的配合力最高,父本自交系以1109的配合力最高.     

Identification of CMS maintainers and restorers for hybrid rice development in Ghana

The cytoplasmic-genetic male sterility is the most widely used system for hybrid rice (Oryza sativa) seed production. It requires three lines: the two hybrid parents (A and R lines) and a third line (maintainer (B line)), which maintains the sterility of the female parent during seed increase. Studies were undertaken to identify maintainers and restorers for introduced cytoplasmic male sterile (CMS) lines using simple sequence repeat (SSR) markers and testcrosses. Molecular screening with SSR marker RM6100 grouped the assembled inbred lines into 30 potential restorers and 55 potential maintainers. One maintainer (WAS 127 -12-1-6-3-1) and 16 restorers were confirmed by testcrosses. WAS 127-12-1-2-3 had higher grain yield per plant in crosses with CMS1 (IR69625A) than the local checks (AgraRice and Jasmine 85) and could be used as a restorer to develop a locally adapted, high-yielding hybrid. Conversion of WAS 127 -12-1-6-3-1 into a local CMS line was stopped because of sterility instability in the BC₁F₁ generation. Continued testcrosses to the set of identified potential maintainers could help identify a stable one that can successfully be converted into a locally adapted CMS line.