Influence of Genetic Drift of Restoring Gene (Rf) on Seed Purity of Yuetai A, a Honglian-Type Cytoplasmic Male Sterile Line in Hybrid Rice

The seed samples of Yuetai A, a Honglian （HL） type cytoplasmic male sterile （CMS） line in hybrid rice were investigated to assess the seed purity and to analyze the cause of off-type plants by imitating the biological contaminant to Yuetai A in Nanjing, Jiangsu Province and Lingshui, Hainan Province during 2004-2006. The seed impurity of Yuetai A mainly resulted from the genetic drift of restoring fertility gene （Rt） after biological contamination but not from its sterility unstability. All of the ten maintainer lines, five restorer lines and three thermo-sensitive genic male sterile lines used in the study could pollinate Yuetai A and Yuetai B to produce F1 plants, directly or indirectly resulting in Rf-gene drifting into Yuetai A and generating ＇iso-cytoplasm restoring-generations＇. Furthermore, high outcrossing rate and similar heading date of Yuetai A with many varieties used in rice production might easily result in the biological contamination. After removing all plants with Rf-gene mixed in Yuetai A and preventing Rf-gene drifting into Yuetai A, the seed purity of Yuetai A and Yuetai B had been raised to 100%.

Development and Application of SCAR Markers for Discriminating Cytoplasmic Male Sterile Lines from Their Cognate Maintainer Lines in Indica Rice

The DNAfragments about 1 600 bp were amplified using random amplified polymorphism DNA （RAPD） primer OPAl2 with the templates of mitochondrial DNA of Zhenshan 97A and Zhenshan 97B, and were sequenced. The nucleotide sequences and lengths of the fragments from Zhenshan 97A and Zhenshan 97B showed no difference. The precise length of the fragment was 1 588 bp. Sequence characterized amplification region （SCAR） primers were then developed to discriminate the cytoplasmic male sterile （CMS） lines and their maintainer lines. A specific 1 588 bp fragment could be amplified with SCAR primers, CHI19F2/CHI19R2 and CHI20F3/CHI23R3, in the mitochondrial DNA of Zhenshan 97A, but not Zhenshan 97B. Furthermore, the specific fragment could be also amplified from the total DNA from green leaf tissues of Zhenshan 97A with SCAR primers, but not Zhenshan 97B. With the corresponding primers, the specific fragment could also be amplified from the total DNA of green leaves of other two CMS lines with wild abortive type cytoplasm （CMS-WA）, namely Zhenpin A and Tianfeng A, but not in their maintainer lines. Moreover, using total DNA as template, each of the four pairs of SCAR primers could also be used to amplify the 1 588 bp fragment in CMS-ID （Indonesia paddy type） line 11-32A but not in 11-32B, and the specific fragment was amplified from the DNA of both F1 and F2 seedlings of Shanyou 63. The results of detecting the genetic purity of a man-made mixture of the seeds of Zhenshan 97A using CHI20F3/CHI23R3 were completely consistent with the phenotypes. Taken together, these results indicated that the specific 1 588 bp-fragment amplified by CHI20F3/CHI23R3 was the unique amplification products of CMS mitochondrial DNA, and could be used to distinguish CMS-WA and CMS-ID lines from their corresponding maintainer lines at the seedling stage.

Genetic Mechanism of Dominant Earliness in Kefeng A,a New Rice Cytoplasmic Male Sterile Line

Kefeng A is an early maturing indica cytoplasmic male sterile （CMS） line of rice. Combinations derived from Kefeng A and late maturing indica restorer lines showed dominant earliness to various extents. To understand the genetic basis of dominant earliness, the genotype of photoperiod-sensitive genes in Kefeng A was analyzed using a complete set of heading time near isogenic lines （NILs） EGO to EG7, ER, LR, T65, T65E^b, T65E^bm, T65m, NIL（Hd1） and NIL（Hd4）. Results indicated that Kefeng A contained two dominant photoperiod-sensitive alleles E1 and Se-1^U on E1 and Se-1 loci, respectively, and the genotype of photoperiod-sensitivity genes for heading time in Kefeng A was E1E1e2e2E3E3Se-1^USe-1UEf-1Ef-1. Based on the detected heading time genotype, in combination with the heading time of Kefeng A and the early maturing phenomenon in its derived F1 hybrids, it is speculated that Kefeng A might carry a dominant inhibitor gene Su-E7 for the dominant photoperiod- sensitive gene E1, and a recessive inhibitor gene i-Se-1 for another dominant photoperiod-sensitive gene Se-1. The reason why F1 hybrids from Kefeng A exhibited early maturing was hereby analyzed and the breeding value of dominant earliness related genes in Kefeng A was discussed.

Differences in Nuclear DNA Between Male-Sterile and Male-Fertile Lines of Sorghum bicolor

Cytoplasmic male sterility(cms)is determined by nuclear-cytoplasmic interactions. Up to now, most studies are focused on the comparison of cytoplasmic DNAs of male-sterile lines and male-fertile lines, and analysis of nuclear DNA has not been documented yet. In order to find out the possible difference in nuclear genome of male-sterile line A1 Tx623 and corresponding male-fertile line Tx623 of sorghum, random amplified polymorphic DNA(RAPD)approach was used to analyze their cytoplasmic and nuclear genomes. Total DNAs of them were amplified at first to screen primers, which were able to generate reproducible bands specific to male-sterile line or male-fertile line. Then the selected primers were used to amplify their mitochon-drial DNA(mtDNA)and chloroplast DNA(cpDNA). The origins of all the polymorphic fragments were analyzed. After ruling out those amplified from cytoplasmic DNA, seventeen polymorphic fragments were determined to be amplified from nuclear DNA. These fragments originated from nuclear DNA indicate that differences in sequence exist between the nuclear DNA of male-sterile line and male-fertile line of sorghum, which do not agree with the traditional standpoint that they have identical nucleus.

Development of New InDel Marker to Detect Genotypes of Rf-1a Conferring Fertility Restoration of BT-Type Cytoplasmic Male Sterility in Rice

Restorer line breeding is an important approach to enhance the heterosis and improve the yields of japonica hybrid rice. To improve the selection efficiency of restorer lines for BT-type cytoplasmic male sterility （CMS） in japonica rice, a functional marker InDeI-Rf-la based on the difference of nucleotide sequence in Rf-la locus between BT-type CMS lines and restorer lines was developed to detect the genotypes of different rice materials. Conventional indica rice varieties, restorer and maintainer lines without 574 bp deletion could restore the fertility for BT-type CMS in japonica rice. By contrast, most conventional japonica rice varieties except Aichi 106 and Yijing 12, with genotype of rf-larf-la showed the 574 bp deletion maintained sterility for BT-type CMS lines. To further verify the effect of genotyping detection in Rf-la locus, this marker was also used to amplify the genomic DNA in different japonica rice restorer lines, CMS lines, hybrids and F2 segregation population, and three genotypes in Rf-la locus could be distinguished distinctly. Therefore, the marker InDeI-Rf-la could be widely used for genetic id^ntifio.~tinn ~nd m^rkp.r-~.~.~i^fp.d .~.tAr.tinn （MA.~ in hr~=dinn i^nnnir~ r^fnr~=r lin==~

Maxie A- a novel cytoplasm male sterile line

The pollen abortion of Maxie A and Zhengshan97 A belong to stainless type with Ksolu-tion.The maiority of Maxie A abortive Pollenstook cireular shape and few was staining abortion

The unstability of cytoplasmic male sterility of Brassica napus L.

The unstability of cytoplasmic male sterilities (CMS) of Brassica napus Lwas stud-ied from 1989 to 1992,and the results indicated: 1. The occurrence of trace-pollen plants In sterilematerials was caused by nuclear polygenes of the maintainers; 2. Progenies of partial sterility typeshowed segregation of sterile, partially sterile (with trace pollen )and fertile plants; 3. High andlow temperature CMS lines were crossed and its progenies manifested complex segregation; 4.There was a tendency to increase the fertility with successive selfing of the high temperatureCMS line.

甘蓝型油菜373S温敏不育基因在可育细胞质背景下的表达

旨在明确甘蓝型油菜温敏不育系373S温敏不育基因表达与特定细胞质之间的关系。以甘蓝型油菜373S(微粉)为父本,以具有cam细胞质的Shaan2B为母本,杂交、回交及自交得到BC_(1)及F_(2)代群体。结果表明,在上述具有cam细胞质的BC_(1)及F_(2)中,可育株与不育株的分离比分别符合3∶1与15∶1,表明该群体中不育性状受2对基因控制。分离群体中的不育株表现出温敏不育特征,其不育花形态与373S没有明显差别;与373S比较,该分离群体中的不育植株结实角果数及自交结实率有不同程度的降低,不育期时间率(不育期时间所占百分比)无显著差异;花冠直径、四强花药长度、二弱花药长度无明显差异,花柄长度、花瓣长度、花瓣宽度、四强雄蕊长度、二弱雄蕊长度略有增加。细胞学观察表明,该分离群体中的不育株小孢子的发育过程、染色体形态、胼胝质沉积与373S无明显差异,均在花粉母细胞时期出现异常。本研究成功地将373S温敏不育基因从pol细胞质导入cam细胞质,说明该温敏不育性状是由细胞核内温敏不育基因导致,与细胞质背景无关。

Restorable variation of cytoplasmic type of male sterile line in rice by in vitro culture

Rice male sterile (MS) lines, IR66707A and IR69700A, which possess the cytoplasm of Oryza perennis and O. glumaepatula respectively, belong to the cytoplasmic type. Their sterility could be maintained but not be restored. By somatic cell culture of these two MS lines, 47 somaclones with 465 R1 plants were obtained. All of the 465 R1 plants were sterile in the spring season in Guangzhou. According to the expression of the R1 plants and the level of similarity to their donor parents, they could be divided into three types. The plants of type I were male sterile. The sterility of some somaclones of this type could be restored by the test crossing varieties or alternated to fertile by changes of some environmental conditions. The hybrid F1 of test cross from the MS somaclones in type I was fertile while the hybrid F1 from the donor MS lines was still sterile. The R1 plants of type Ⅱ were similar to the donor parents and also male sterile. The hybrid F1 from all of the plants of type Ⅱ crossed to test

Lodging Resistance of Aromatic CMS Line Zhongzhe A and Its Derived Lines

Nineteen rice combinations derived from Zhongzhe A and its derived lines, as well as Y Liangyou 1 as the control, were used to study lodging resistance by detecting plant height and some of the traits of culm and panicle that are related to lodging. The results indicated that the lodging resistance of 16 combinations was significantly stronger than that of Y Liangyou 1. Moreover, the lodging resistances of all combinations derived from Zhongzhe 2A, Zhongzhe 3A, Huazhe A and Zhong 1A were significantly higher than that of Y Liangyou 1. Additionally, the traits related to lodging were not identical within different CMS rice lines, and the relationship between plant height and lodging resistance was only significantly (P < 0.01) detected in Zhongzhe 2A. Some traits of the second internode were closely related to lodging in all combinations, which can be used as an effective index in lodging resistance breeding in rice.

结球甘蓝系列杂交种(GL22)的选育

【目的】利用自有结球甘蓝种质资源,根据市场对口感型、鲜食型品种的需求,选育出更多性状优良、符合市场供需的结球甘蓝品种。【方法】以团队前期选育的13个结球甘蓝Ougra不育材料为母本,10个结球甘蓝自交系材料(GL14000-14009)为父本,通过杂交,配制14个结球甘蓝杂交组合材料,分别从开展度、外叶数、纵径、横径、中心柱长度、品质测定、品质鉴定、产量和抗病性等方面进行比较筛选。【结果】筛选出的4个结球甘蓝杂交组合材料GL22-02、GL22-06、GL22-11和GL22-13,在农艺性状、优质性和产量均优于对照种特加2号,叶球均呈圆球型,帮叶比分别为26.9%、20.8%、23.1%和16.8%,均优于对照种(31.3%);叶球紧实度分别为0.76、0.73、0.59和0.62 g/cm^(3),比对照种高0.16 g/cm^(3)以上;中心柱长度均小于叶球高的1/2,分别为4.9、4.3、4.8和4.6 cm;水分含量分别为93.22%、94.17%、93.75%和93.61%;蛋白质含量分别为1.51%、1.28%、1.39%和1.36%;可溶性糖含量分别为5.61%、5.69%、5.56%和5.84%,比对照种高0.14~0.37个百分点;粗纤维含量分别为0.61%、0.71%、0.69%和0.67%,比对照种低0.08~0.18个百分点;维生素C含量分别为682.3、687.1、699.1和682.3 mg/kg,比对照种高48.4~65.2 mg/kg;经食用品质鉴定,筛选出的结球甘蓝4个杂交组合材料,叶球生(鲜)食,质地脆嫩,口感较甜。结球甘蓝组合材料的黑腐病抗病能力均为高抗(HR),且与对照种相同;产量分别比对照种增产4.80%、8.46%、10.97%和8.46%。【结论】筛选出的GL22-02、GL22-06、GL22-11和GL22-134个组合材料,综合农艺性状和经济性状优良,可进一步大面积推广示范。

万寿菊雄性不育两用系抗氧化酶活性分析

为了解万寿菊雄性不育两用系活性氧代谢的特点,本研究以万寿菊雄性不育两用系2-2为试验材料,分别测定不育株和可育株在不同生长时期叶片及花蕾的过氧化物酶(POD)、抗坏血酸过氧化物酶(APX)、过氧化氢酶(CAT)、超氧化物歧化酶(SOD)4种抗氧化酶的活性及丙二醛(MDA)和抗坏血酸(AsA)的含量,分析育性与抗氧化酶活性、抗氧化物质的关系。结果表明:叶片中可育株的POD、APX、CAT活性总体高于不育株,花蕾横径在1.1~1.5 cm时,4种抗氧化酶均表现为不育株高于可育株,不育株抗氧化物质MDA、AsA含量逐渐积累,说明抗氧化酶和抗氧化物质的变化与万寿菊的育性密切相关。本研究为万寿菊雄性不育的成因提供了一定的理论依据,为雄性不育两用系进一步高效制种、育种奠定了基础。

朝天椒新品种‘石辣6号’的选育

‘石辣6号’是以辣椒核质互作型雄性不育系T108A为母本,恢复系Q1-352C231为父本杂交配制而成的朝天椒一代杂交种。中熟,平均始花节位14.5节,播种到红熟131 d。单株挂果210个左右,单果质量4.6 g左右。果实小羊角形,果面微皱,果纵径9 cm,果横径1.3 cm,果肉厚1.4 mm,平均制干率27.81%。辣椒素总含量1.33 g/kg,辣度2.05万SHU。在西南地区一般每667 m^(2)产鲜红椒1 500 kg左右,田间表现高抗疫病、抗病毒病、高抗细菌性叶斑病。该品种为鲜食加工兼用型品种,加工品质好,适宜在西南地区海拔高度500~1 500 m及相似区域作春夏露地及早春地膜覆盖种植。

F型小麦雄性不育系小孢子发育的细胞学观察

为明确F型小麦雄性不育系雄性败育的细胞学机理,以西农979为对照,采用醋酸洋红染色制片等方法观察花粉母细胞减数分裂、小孢子发育过程及成熟花粉粒育性表现,并套袋自交,于成熟期统计结实率。结果发现,F型小麦雄性不育系仅有2.15%的花粉母细胞减数分裂Ⅱ异常,其余绝大多数花粉母细胞减数分裂正常,但小孢子由单核期进入二核期后,生殖核和营养核先后降解,导致无核小孢子的出现,其比率为77.04%。成熟花粉粒经1%I2-KI染色后显示异常的花粉粒比率高达94.8%,其中包括圆败、典败和染败类型,但以染败型为主。F型小麦雄性不育系套袋自交结实率为2.5%。上述三方面的研究结果彼此相符,据此认为,小孢子由单核期进入二核期后,生殖核和营养核先后降解导致无核小孢子的产生是F型小麦雄性不育系雄性败育的主要细胞学原因。

高粱雄性不育系、保持系正负极向过氧化物酶同工酶的电泳比较

对高粱雄性不育系、保持系不同生长发育阶段叶片中的正、负极向过氧化物酶同工酶进行了检测。结果表明,叶片中正极向过氧化物酶同工酶谱两者基本相同,说明正极向过氧化物酶在不同生长发育时期是稳定的。负极区域中,在叶片发育过程中有2条酶带消失,证明在这个区域中遗传信息出现顺序表达现象。花粉粒发育过程中,不育系的正极向过氧化物酶带始终多于保持系。作者认为,不育细胞质基因可影响编码过氧化物酶的核基因的表达,引起雄性不育。不育细胞质基因可能也同时具有调节基因的功能,表现为具有解除阻遏的作用,使不育系花粉粒发育过程中部分过氧化物酶基因得以表达;而保持系不具有这种解除阻遏的细胞质不育基因,使部分基因仍处于阻遏状态,造成保持系中过氧化物酶同工酶谱带少于不育系的现象。不育细胞质基因的这种调控作用,同样有可能影响核基因遗传功能的正常发挥,引起核质之间的不协调而导致雄性不育。

不同小麦雄性不育类型光合、生理参数日变化的研究

利用2套同核异质的K、T、V、CHA型不育系及其保持系，对其不同生育时期净光合速率（Pn）、气孔导度（Ga）、蒸腾速率（r）、水分利用率（WUE）、光量子通量密度（PFD）和细胞间隙CO2浓度（Ci）、气孔限制值（Ls）等光合、生理参数的日变化及其差异进行比较研究，探讨不同小麦雄性不育类型的胞质效应。结果表明，供试材料净光合速率的日变化均呈双峰曲线，有明显的光合“午休”现象，Pn与Gs、Ci的相关系数分别为0．8187、0．8136，呈显著正相关（r0.05=0．8110），与Ls的相关系数为-0．8496，呈显著负相关（r0.05=0．8110），Pn的午间下降伴随着Gs、Ci，的下降和Ls的升高，表明其主要受气孔因素限制；与保持系的Pn值相比，CHA型和K、T、V型不育系分别降低0．88、2．76、3．30和2．04pmolCO2m^-2s^-1，产生不同程度的负效应，尤以T型和K型最明显。在水分利用率上，K、T、V型不育系较保持系降低0．94—1．54μmol CO2mmol～H2O，负效应显著；CHA型不育系较保持系低0．36μmolCO2mmol^-1H2O,差异不显著，说明CHA对旗叶水分利用率无明显的不良影响。Pn值因母本基因型的不同而异，冀5418及相应不育系的Pn值较太911289的高，差异达显著或极显著水平。因此，选择优势效应大的保持系回交，有利于降低不育胞质对小麦光合功能的负效应。

K型杂交水稻的选育与研究

利用粳籼杂交后代出现的不育株作细胞质雄性不育供体，先后育成了Ｋ青Ａ、Ｋ１９Ａ和Ｋ１７Ａ等籼型不育系。育成的Ｋ型杂交水稻新组合已有５个通过四川省品种审定。初步研究发现，Ｋ型胞质对提高柱头外露率和开花累积率的作用明显优于ＷＡ型胞质；在可恢性及主要数量性状上的胞质效应与ＷＡ型和Ｄ型胞质差异较小。花药发育的细胞学显示Ｋ型不育系花粉败育发生在单核后期，少量花粉发生在二核期，败育花粉以典败为主。Ｋ１７Ａ和Ｋ青Ａ花药的酯酶和过氧化物酶同工酶谱与汕Ａ存在差异。随机扩增多态性ＮＤＡ（ＲＡＰＤ）分析表明Ｋ型胞质与ＷＡ型和Ｄ型胞质的线粒体基因组存在组织结构差异。

粳稻三系亲本的性状特征与杂种优势分析

收集具有代表性的BT型粳稻不育系、保持系及恢复系各16个,共配制229个杂交粳稻组合,就三系亲本的性状特征、粳稻的杂种优势、不同性状亲子间的相关性进行了研究。结果表明:(1)恢复系和保持系的潜在库容相近,但恢复系分蘖性较弱、结实率和千粒重较低,单株产量显著低于保持系。恢复系的垩白度显著高于保持系,直链淀粉含量极显著低于保持系。改良外观品质和提高结实率是今后恢复系选育的主要目标。(2)杂交粳稻普遍存在较强的中亲优势,多数性状的超亲优势不强,但在生长势上则表现非常明显的竞争优势。杂交粳稻大穗优势突出,但结实率多表现负向优势,是目前制约杂交粳稻产量优势发挥的主要限制因素。(3)杂种的多数性状由不育系和恢复系共同决定,杂种与中亲值的相关性最好。比较而言,抽穗期、穗总粒数等性状与不育系关系较为密切,株高、穗实粒数、结实率、品质性状与恢复系关系较为密切。

红莲型不育细胞质在杂交粳稻育种中的应用

为了探讨红莲型不育细胞质应用于杂交粳稻育种的可能性,利用包台(BT)型、红莲(HL)型、茶野(CL)型、野败(WA)型等4种细胞质的同核异质不育系六千辛A与181个粳稻亲本测交,根据测交F1的小穗育性,筛选HL型粳稻恢复系。在此基础上,对筛选出的HL型粳稻恢复系与更多HL型不育系复测,并进行不同细胞质杂交粳稻的比对试验。研究结果表明:1)HL型和CL型不育系的恢、保关系十分一致,测交F1小穗育性间的相关性达极显著水平。2)HL型和CL型粳稻不育系的可恢性虽不如BT型不育系,但明显优于WA型粳稻不育系;以测交F1小穗育性达到85%以上作为选择标准,从BT型恢复系和广亲和恢复系中筛选出25个HL型(CL型)粳稻恢复系。3)不育系的核背景对杂种育性有影响,HL型六千辛A可恢性最好,其次为HL型陵香A,HL型珍5A可恢性最差。4)与BT型不育系配制的杂种相比,HL型和CL型不育系配制的杂种育性稳定性相对较差。5)HL型不育系配制的杂种与BT型、WA型不育系配制的杂种在播种至抽穗历期、株高、产量及品质性状上均无明显差异;HL型不育系配制的杂交粳稻结实率正常,与BT型不育系配制的杂种无明显差异,明显高于WA型不育系配制的杂种。说明HL型不育细胞质应用于杂交粳稻育种是可行的。