Development of Maweizhan cytoplasmic male-sterile line in rice(Oryza sativa L.)

A male sterile mutant plant was found from the rice field of the local rice variety which was cultivated for a long time in the west of Hubei Province. The plant has more vigorous tillering ability. Its plant height of 95 cm was a bit shorter than that of the normal ones. The plant type, the leaf shape and the color of leaf sheath and glume tip of this mutant were identieal to that of the normal plant whereas the color of arrowhead-shape anther was milky white. This mutant set no seed during self-pollination. When it was crossed with IR24. IR26, Minhui 63 or Xieqing-zaoxuian. the Ffertilities were normal. The fertility of this mutant could be restored by IR24, IR26 and Minhui 63 and maintained by Xieqing-zaoxian. Maxie A was developed in 1987 by the successive backcrossing of the mutant with Xieqing-zaoxian. The percentage of abortive pollen in Maxie A in uninucleate microspore to early binucleate microspore stage is

Characterization of Fertility Alteration in 8 Environment-sensitive Genic Male-sterile Lines of indica Rice

Eight indica ( Oryza sativa L.) environment-sensitive genic male-sterile (EGMS) lines, 2-2S, K1405S, F131S, 2136S, Pei-Ai 64S, 1290S, GD-IS and N17S, were sequentially seeded with 10-15 d interval at three sites, Wuhan in 1997, Guiyang in 1997 and Sanya in 1997 and 1998, China. The results of investigations on self-sterilities showed that all of eight EGMS lines had stable sterile periods of longer than 30 d at Wuhan. They can be used for seed production of two-line hybrid rice, but can not reproduce themselves. Their stable sterile periods were shorter than 30 d at Guiyang, they can reproduce themselves and can not be used for hybrid seed production. In Sanya, their stable sterile periods were longer than 150 d, all of eight lines can be used for seed production in summer and autumn and reproduce themselves in winter. The fertility of all eight lines were sensitive to temperature. The sensitive stages, sensitive duration and critical point of temperatures (CPT) of fertility alteration in various lines were different. The sensitive stages of 2-2S and K1405S were from 18 d to 9 d before heading, the sensitive durations were 7-10 d and the CPTs were 23.7-24.5 degreesC. The sensitive stage, sensitive duration and CPT of F131S were from 17 to 5 d before heading, 13 d and 24.3-24.7 degreesC, respectively. The sensitive stage, sensitive duration and CPT of 2136S were from 18 to 12 d before heading, 7 d and 24.6-25.1 degreesC:, respectively. The sensitive stages, sensitive durations of Pei-Ai 64S, 1290S, N17S and GD-1S were from 24 to 13 d before heading and 10-13 d. And their CPTs were 24.6-25.1 degreesC, 25.5-26.2 degreesC, 25.4-26.1 degreesC,, and 24.1-24.7 degreesC, respectively.

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.

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.

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.

Preliminary Studies on the Effect of Photoperiod and Temperature on Male Fertility of a Cytoplasmic Male Sterile Line in Wheat

[Objective] The study aimed to reveal the effect of photoperiod and temperature on male fertility of cytoplasmic male sterile line Vtai911289a in wheat and discuss the mechanism of male fertility alteration. [ Method ] The sowing-date tests and designed conditions were conducted during 2003 -2005. [ Result] Fertility of Vtai911289a, could alter under specific photoperiod and temperature conditions. Temperature is one of the main factors influencing male fertility of the male sterile lines. Vtai911289a, showed stable sterility under the condition of the mean of daily temperature at fertility sensitive stage lower than 19℃ and presented partial fertility when the mean of daily temperature at fertility sensitive stage lower than 20 - 22℃. Photoperiod to some extent affects the male fertility of Vtai911289a, long-day condition is helpful for the male fertility of the sterile line. [ Conclusion] The application of photoperiod temperature-sensitive cytoplasmic male sterile line in production has a higher safety than that of temperature sensitive sterile line.

Application of hybrids with cytoplasmic male-sterility in Zea mays L.in China

The abortive behaviour and the cytoplasm quality of cytoplasmic male-sterility(CMS)lines of homocaryon were investigated and the existence of C race of Bipolaris maydiswere discussed from the point of view of genetic breeding,physiology and pathology in this paper.Then the countermeasures to prevent the danger from disease of B. maydis in CMS hybrid pro-duction were proposed.

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%.

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.

Studies on the Recross Heterosis Effect of Male-sterile Single-hybrids in Corn

Re-cross was conducted between five ES cytoplasm male-sterile hybrids and four high-oil hybrids, and five normal hybrids, respectively. The oil content, yield, 1000-kernel weight and kernel size were estimated. Results were as follows: The average kernel oil content in the male-sterile hybrid ×high-oil hybrid was 1.6% higher than that of the female parent. The xenia effect value of oil genes was 0.30. The yield and 1000-kernel weight of male-sterile hybrids were 10.1% and 5.8% higher than that of corresponding fertile hybrids respectively, which showed significant cytoplasm effect. The yield of the male-sterile hybrid × high-oil hybrid was similar to that of the female parent, but its 1000-kernel weight was 7.3% lower than that of the female parent. Compared with the high-oil male parent, grain yield, 1000-kernel weight and kernel size of the male-sterile hybrid× high-oil hybrid were higher. Seed-filling rate, the days of seed-filling and IAA content in the male-sterile hybrid × high-oil hybrid showed average heterosis tending the female parent, which may be perhaps one of the reasons resulting in the average heterosis tending to the female parent on kernel oil content, yield, 1000-kernel weight and kernel size.

Experimental and genomic evidence for the indica-type cytoplasmic effect in Oryza sativa L.ssp.japonica

Cytoplasmic effects are important agronomical phenomena that have generated widespread interest in both theory and application. In the present study, five high yield rice cultivars（Oryza sativa L. ssp. japonica） in large-scale cultivation in northeast China were determined to possess Oryza sativa L. ssp. indica-type cytoplasm using cytoplasmic subspecies-specific molecular markers. This was confirmed by cytoplasmic genome-wide single nucleotide polymorphisms（SNPs） and functional gene sequencing. Two of these five japonica cultivars were core breeding parents with high yield and the other three were super-high-yield varieties registered by the Ministry of Agriculture of China. We constructed nuclear substitution lines to further demonstrate whether and how this indica-type cytoplasm contributed to yield improvement by comparing yield components. The results showed that under the same japonica nuclear background, the lines with indica-type cytoplasm had a significant decrease in tillers in exchange for increased grain number per panicle compared with their recurrent parents. Our results implied that botanical basis of this cytoplasmic effect was to reduce the plant＇s branching differentiation to produce more floral organs under the constant nutrition. Our findings open another door for the utilization of inter-subspecific hybridization for the improvement of rice cultivar.

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

Analysis of Heterosis, Combining Ability and Heritability of Cadmium Content in Brown Rice of Three-line Indica Hybrid Rice

Five cytoplasmic male sterile （CMS） lines were used as parents in an incomplete diallet cross and six restorer lines of rice design （Nc II design）. Thirty hybrid combinations with the same growth period were selected as experimental ma- terials to investigate the heterosis, combined ability and heredity of Cd content in brown rice of indica hybrid rice. According to the results, Cd content in brown rice showed a significantly negative heterosis; the general combining ability and specific combination ability of Cd content in CMS and restorer lines both reached extremely significant level （P〈0.01）, indicating that both genetic improvement of parents and e- valuation of combinations are important to the breeding of hybrid combinations with low accumulation of Cd; the broad-sense heritabitity and narrow-sense heritability of Cd content were both relatively high with slight differences, which respectively reached 97.73% and 80.10%, indicating that Cd content in brown rice mainly de- pends on the additive action of genes; in addition, parent improvement showed bet- ter effect on the selection of early generation.

辣椒核质互作雄性不育三系的选育

为解决辣椒人工去雄制种成本高、种子纯度难以保障的问题,促进辣椒产业的良性发展,开展了辣椒核质互作雄性不育三系的选育。首先从代号为149的辣椒后代中发现了不育株,然后通过杂交、回交和自交的育种手段,选育出了辣椒不育系BC_(8)149A-2、保持系F_(10)149B-2、恢复系WYS-1。经不育系与保持系杂交效果稳定性试验,保持系F_(10)149B-2对不育系BC_(8)149A-2的不育性恢复效果达到100%,是一对合格的不育系和保持系;经不育系与恢复系产量配合力测定,不育系BC_(8)149A-2与恢复系WYS-1杂交产量配合力表现最好,均显著高于对照哈椒6号。三系的获得提高了制种效率,降低了制种成本,解决了人工去雄不彻底而造成种子纯度不高的问题,为辣椒核质互作雄性不育三系的选育提供了参考。

A Study on Comparative Fertility Restoration in A2 and A4 Cytoplasms and Its Implication in Breeding Hybrid Pigeonpea [Cajanus cajan (L.) Millspaugh]

Exploitation of hybrid vigour has been visualized as the most efficient option for increasing productivity in pigeonpea [Cajanus cajan (L.) Millspaugh]. Cytoplasms from various wild relatives of pigeonpea have been transferred to develop CMS lines in the background of cultivated pigeonpea. However, A2 (Cajanus scarabaeoides) and A4 (Cajanus cajanifolius) cytoplasms have been utilized most frequently. In order to study fertility restoration efficiency in F1 hybrids having either A2 or A4 cytoplasms, an experiment was conducted at the Indian Institute of Pulses Research (IIPR), Kanpur during 2008-2012. Four CMS lines namely Hy4A, H28A (each with A2 cytoplasm), ICP 2039A and ICP 2043A (both with A4 cytoplasm) were crossed with ten genotypes/restorers of long duration pigeonpea for two years. The F1 hybrids so-obtained were assessed in the succeeding years for pollen fertility and pod setting. All the pollinators except IPA 203 restored fertility in F1 hybrids derived from ICP 2039A and ICP 2043A (both having A4 cytoplasm). However, none of the restorers were effective in restoring fertility in hybrids derived from Hy4A and H28A (each with A2 cytoplasm). This could be ascribed to undesirable linkage drag still present in these two CMS lines having A2 cytoplasm. The F2 progenies derived from 4 hybrids (ICP 2039A × NA-1, ICP 2039A × Bahar, ICP 2043A × NA-1 and ICP 2043A × Bahar) segregated approximately into 3 fertile: 1 sterile plants. However, 2 F2 progenies having Pusa 9 as the restorer revealed approximately 15 fertile:1 sterile ratio. Thus monogenic and digenic duplicate gene action with complete dominance for fertility restoration was observed in F1 hybrids derived from CMS lines having A4 cytoplasm. F3 progenies from individual F2 plants of these crosses also confirmed the same pattern of fertility restoration. This study indicated that CMS lines based on A4 cytoplasm would be more desirable as these might have more number of restorers compared to those having A2 cytoplasm.

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。

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。

水稻同核异质广亲和不育系细胞质效应的研究

利用同核异质广亲和不育系真系秋光 A,研究 3种不育细胞质对杂交稻 16个性状的遗传效应。结果表明 :(1)不育细胞质在结实率、每穗实粒、单株产量、株高 4个性状上表现显著的负效应 ,在抽穗期、千粒重 2个性状上表现显著的正效应 ,单株穗数、每穗总粒及 8个品质性状不育细胞质效应不显著 ,不育细胞质效应与相对效应的分析结果基本一致 ;(2 )不育细胞质遗传效应的大小与细胞质的可恢复性有关 ,BT型细胞质的可恢复性较好 ,细胞质效应较小 ,WA型细胞质最难恢复 ,细胞质效应最大 ;(3)品种间组合和亚种间组合的不育细胞质效应无显著差异 ,但杂种不育细胞质效应的大小与恢复系恢复力的强弱有关 ;(4 )某性状不育细胞质效应的大小和有无决定于该性状与育性性状的密切程度。

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。