Establishment of a random-mating population of 'Polima' CMS restorers in Brassica napus by use of dominant genie male sterility

Five restorers of ‘polima’ cytoplasmic male sterility (pol CMS) cannot restore the fertility in dominant genie male sterility (DGMS). A dominant male sterility gene from both, a DGMS line Rs l046AB and DGMS hybrid ‘Zhongza No. 3’, was successfully introduced into Polima cytoplasm. A random-mating population of pol CMS restorers was established by using many double-low pol CMS restorers as pollinators to cross continuously to the DGMS plants which had Polima cytoplasm.     

Identification of stable maintainer and fertility restorer lines for 'Polima' CMS in Brassica campestris

‘Polima’ cytoplasmic male sterility (CMS) was transferred from ‘Polima’ Brassica napus ‘ISN 706’to five different cultivars of Brassica campestris (‘Pusa kalyani’, ‘Pant toria’, ‘Candle’, ‘Tobin’ and ‘ATC 94211′) by repeated backcrossing. It was observed that, while ‘Polima’ CMS manifested complete and stable male sterility in the nuclear backgrounds of ‘Pusa kalyani’, ‘Pant toria’, and ‘Tobin’, the cultivars ‘Candle’ and ‘ATC 94211’possessed the restorer gene for this CMS in the heterozygous condition. An analysis of F₁ and F₂ generations of ‘Polima’‘Pusa kalyani’בCandle’ and ‘Polima’‘Pusa kalyani’בATC 94211’ revealed that restoration is controlled by a single dominant gene. Identification of stable maintainers and restorers of ‘Polima’ CMS could facilitate the development of hybrid varieties in B. campestris.     

甘蓝型油菜细胞核 细胞质雄性不育三系的研究与利用 Ⅳ.隐性细胞核 波里马细胞质雄性不育三系的创建

甘蓝型油菜隐性细胞核雄性不育与波里马细胞质雄性不育可能具有完全不同的不育基因系统;采用有性杂交和连续回交的方法,将甘蓝型油菜隐性细胞核不育基因导入到含有波里马不育细胞质的基因型中,并得到甘蓝型油莱隐性细胞核 波里马细胞质雄性不育系RGCMS—S45A和RGCMS—117A及其相应的保持系S45B和117B;采用测交方法,从隐性细胞核雄性不育系中筛选出甘蓝型油菜隐性细胞核 波里马细胞质雄性不育保持系9个;波里马细胞质雄性不育的恢复系均是隐性细胞核 波里马细胞质雄性不育的恢复系。     

Cytological observation of anther structure and genetic investigation of a new type of cytoplasmic male sterile 0A193‐CMS in Brassica rapa L.

Cytoplasmic male sterility (CMS), a maternally transmitted failure in pollen formation, is an effective pollination control system in hybrid rapeseed (Brassica napus) breeding. However, CMS is not widely used in the related oilseed species Brassica rapa. In the past years, several male sterile plants have been isolated from the B. rapa landrace ‘0A193’, collected in Shaanxi, China, in 2011. It is noteworthy that the fertility expression of 0A193‐CMS was affected by temperature. In contrast to pol CMS, fertility tests with 18 B. rapa and 9 B. napus accessions suggest that a different system of maintaining and restoring is responsible for the observed phenotype. Further on, genetic investigation evidenced that fertility of 0A193‐CMS is controlled by both cytoplasmic and one pair of nuclear recessive genes. Interestingly, plants of the 0A193‐CMS type possess a highly specific fragment of the mitochondrial gene orf222, a crucial regulator of male sterility in nap CMS. Our study broadens the CMS resources in B. rapa and provides a highly applicable alternative to pol CMS and ogu CMS for hybrid breeding production.     

Tournefortii male sterility system in Brassica napus. Identification, expression and genetic characterization of male fertility restorers

A germplasm collection of 152 diverse rapeseed accessions from Canada, China, France, India, Poland and South Korea was assayed for identifying new fertility restorers and sterility maintainers for a Tournefortii (tour) cytoplasmic male sterility (CMS) system in rape‐seed. Only 16 (10.5%) genotypes showed complete fertility restoration following hybridization with tour CMS line NE 409A. Notable among these were GSL 8851, GSL 8953, Mokpo # 9, Mali, Buk‐wuk‐13, Kuju‐27 and Mokpo # 84. As many as 78 (51.3%) genotypes were perfect maintainers of sterility, the remaining 58 (38.2%) genotypes were classified as partial maintainers. To study the inheritance of fertility restoration, 20 CMS (tour) rapeseed lines were crossed with the four best fertility restorers, namely GSL 8851, GSL 8953, Kuju‐27 and Mokpo # 9, to obtain F₂ and test cross populations. Segregation data indicated that fertility restoration for tour CMS was governed by two genes, of which, one is stronger than the other (χ²_12:3:1). Differences in gene interactions were also observed (χ²_9:3:4) which could be explained on the basis of influence of female parent genotypes/or modified expression of the restorer gene(s) in different genetic backgrounds. Tests of allelism indicated that the restorer genes present in the four restorers evaluated were allelic.     

Identification and Inheritance of Fertility Restorer Genes for 'tour' CMS in Rapeseed (Brassica napus L.)

Eighteen genotypes of Brassica napus were crossed to a cytoplasmic male sterile (CMS) line of B. napus BO 15 carrying B. tournefortii cytoplasm (‘tour’ cytoplasm). Fourteen genotypes were found to be stable maintainers of the ‘tour’ CMS. Of the remaining four genotypes, GSL-1 and ‘Asahi-natane’ were found to be heterozygous and ‘Mangun’ and ‘Yudal’ were homozygous for the restorer gene. Analysis of the F₁ and F₂ progenies of (CMS) BO 15 בMangun’ and (CMS) BO 15 בYudal’ showed that fertility restoration is controlled by a single dominant gene. The availability of a number of stable maintainer lines and the simple inheritance pattern of fertility restorer gene makes ‘tour’ CMS a useful system for hybrid seed production in rapeseed.     

一个白菜型油菜细胞质雄性不育的遗传研究

１９９３年春在白菜型油菜品种“浠水白”中发现了几株雄性不育株,遗传研究结果表明,“浠水白”雄性不育株为细胞质雄性不育,所有调查过的白菜型油菜品种（系）均具有这种雄性水育的保持系。与ｐｏｌ ＣＭＳ和ｎａｐＣＭＳ的保持系和恢复系的测交结果表明,“浠水白”雄性不育与ｎａｐ ＣＭＳ具有相同的恢保关系,与ｐｏｌ ＣＭＳ具有完全不同的恢保关系。ＥｃｏＲⅠ,ＨｉｎｄⅢ,ＰｓｔⅠ和ＳａｌⅠ四种限制性内切酶的线粒体     

中国甘蓝型油菜细胞质雄性不育的主要类型及在育种实践中的应用

我国甘蓝型油菜细胞质雄性不育的类型主要有：ogura CMS、nap CMS、pol CMS、Shan 2A CMS、Hau CMS、NCa CMS、Nsa CMS和NEA CMS。pol CMS和Shan 2A CMS在我国油菜杂种优势利用中发挥着重要的作用。新型不育胞质的育成以及在育种上的应用,不仅丰富了细胞质雄性不育种质资源,而且为我国油菜产业可持续发展提供了保证。     

Identification of a Stable Maintainer Line for 'Polima' Cytoplasmic Male Sterility in Rapeseed (B. napus L.)

‘Polima’ cytoplasmic male sterility (CMS) was transferred to three different genotypes of B. napus i.e. GSL-1, ISN706 and HNS-8 by repeated backcrossing and was found to be completely stable in the nuclear background of synthetic B. napus genotype, ISN706, derived from a cross B. campestris ssp. oleifera var. brown sarson ×B. oleracea var. botrytis cv. Tusa Katki'. The BC₅ and BC₆ generation lines of ISN706, GSL-1 and HNS-8 with ‘Polima’ CMS were grown under a range of temperature and photo-period conditions to test their stability. No breakdown in sterility was observed in ‘Polima’ ISN706 and, therefore, this genotype can be used as a maintainer for hybrid seed production.     

Breeding a genie and cytoplasmic double-MS line of rapeseed (Brassica napus L.)

All rapeseed lines with Polima male sterility (MS) that are applied in hybrid cultivars have the problem that their sterility varies with temperature. To overcome this problem, two double-MS lines with genie (GMS) as well as cytoplasmic male sterility (CMS) genes were synthesized through seven generations of breeding, based on a systematic study of changes in fertility of the genie and cytoplasmic male sterility lines. The fertility of the new sterility lines was determined by observation of the floral organs and by pollen staining. The results showed that, in the double-MS lines, half the plants maintained the features of the Polima CMS line, while the other half behaved like the GMS line. The GMS genes were correctly expressed in the Pol cytoplasm, but there was little interaction between the GMS and CMS genetic systems.     

Identification of ‘Sib’ plants in hybrid cauliflowers using microsatellite markers

Hybrid cauliflowers have been developed to exploit heterosis and to improve uniformity of production. Two breeding systems are commonly employed, self-incompatibility (SI) and cytoplasmic male sterility (CMS). Sibs, assumed to be self-inbred, often contaminate hybrid seed lots in the SI system and whilst self-inbreeding is not possible in the CMS system, plants that look like sibs occur. The objective of this study was to develop microsatellite markers for male and female cauliflower parent lines of both SI and CMS systems and to use them to screen sibs and aberrant plants in F₁ hybrids. Fifty six pairs of microsatellite primers were screened and 8 primer pairs produced co-dominant markers in parent plants and two pairs of markers were chosen for purity testing of F₁ hybrid seeds. Controlled pollinations were conducted in the glasshouse to produce hybrid and selfed-seeds. These seeds were grown in a field trial to identify morphologically normal and sib plants and to assess the reliability of microsatellite markers in detecting sib plants. Microsatellite analysis of morphological sib plants from the SI system revealed that these were not always self-inbred, in contrast, most self-inbred plants showed normal growth. Similarly, all morphological sibs from the CMS system showed hybrid bands. This suggests that morphological sibs were not always due to selfing but possibly to an interaction between genetic and environmental factors and this requires further investigation.     

Identification and transfer of a new cytoplasmic male sterility source from Oryza perennis into indica rice (O. sativa)

Summary Most of the commercial hybrids of indica rice are based on wild abortive (WA) source of cytoplasmic-genetic male sterility (CMS). Such cytoplasmic uniformity may lead to genetic vulnerability to disease and insect pests. To overcome this problem, diversification of CMS sources is essential. Crosses of 46 accessions of O. perennis and two accessions of O. rufipogon as female parents were made with two restorers (IR54, IR64) of WA cytosterility. Sterile hybrids were backcrossed with the respective recurrent parents. Of all the backcross derivatives, one line having the cytoplasm of O. perennis Acc 104823 and the nuclear background of IR64 was found to be stable for male sterility. The newly developed CMS line has been designated as IR66707A. This line is completely sterile (0% seed set) under selfed conditions. Crosses of IR66707A with 10 restorers of WA cytoplasm showed almost complete (93–100%) pollen sterility, indicating that the male sterility source of IR66707A is different from WA sterility. Southern hybridization of IR66707A, O. perennis (cytoplasmic donor), IR66707B (maintainer) and V20A (WA cytoplasm) using mitochondrial DNA specific probes (5 endonucleases × 8 probes) showed identical banding patterns between IR66707A and O. perennis. However, in more than half of the combinations, different banding patterns were observed between IR66707A and IR66707B and between IR66707A and V20A. The results suggest that IR66707A has the same cytoplasm as the donor (O. perennis), and CMS may not be caused by any major rearrangement or modification of mtDNA. The new CMS source identified will be useful in cytoplasmic diversification in hybrid rice breeding.     

Cytological and molecular characterization of a new cytoplasmic male sterility in rapeseed

It is very important for rapeseed hybrid production to develop and utilize a novel cytoplasmic male sterility (CMS) system concerning the possible risk because of a narrow cytoplasm background. Here the anatomy of anther development in the CMS system, named NCa , was observed using light microscope and transmission electron microscope, and the restriction fragment length polymorphism (RFLP) analyses of mitochondrial DNA of NCa sterile line were also performed in comparison with the other rapeseed sterile lines, such as pol , nap , ogura , and tour . The anther abortion of this CMS line occurred at the later uninucleate microspore stage, and the anatomic aborting characteristics were obviously different from all the other rapeseed CMS lines reported before. The RFLP analyses revealed that five probe/enzyme combinations could distinguish the five CMS lines. The results of anatomic observations and mitochondrial DNA polymorphism indicated that the NCa CMS system is a novel one which differs from the pol , nap , ogura , and tour systems.     

体细胞杂交在油菜细胞质雄性不育创建和改良中的应用

油菜细胞质雄性不育作为生产油菜杂交种的主要授粉控制系统得到广泛利用，但由于油菜种内自然发生的有利用价值的雄性不育细胞质类型不多，所以种属间转移现有不育细胞质及发掘新型不育细胞质意义重大。体细胞杂交不仅避开了有性杂交亲和障碍的限制，还可实现两个杂交亲本细胞质基因组的重组，是一种快速有效、应用广泛的转移和诱导雄性不育细胞质的手段。本文综述了利用原生质体杂交技术在油菜种内、种间和属间转移雄性不育细胞质以及通过细胞质基因组重组改良和创建新型雄性不育细胞质的研究进展，并讨论了利用体细胞杂交方法创建新型雄性不育细胞质的应用前景。     

Identification of restorers and maintainers for developing basmati and non-basmati hybrids in rice, Oryza sativa

Twenty‐seven improved aromatic lines of germplasm and 18 non‐aromatic disease‐resistant genotypes of rice were test‐crossed with four cytoplasmic male‐sterile lines (IR 58025A, IR 62829A, PMS 3A and PMS 10A). Thirteen aromatic and 10 non‐aromatic genotypes were selected based on pollen fertility, and crosses were repeated to confirm sterility‐maintaining and fertility‐restoring ability. Genotypes were categorized as effective restorers (> 80% spikelet fertility), partial restorers (21‐79% spikelet fertility) and maintainers (< 1% spikelet fertility). The effective basmati restorers identified were Basmati 385, Chandan, P1031‐8‐5‐1, HKR 241‐IET‐12020, SAF Khalsa 7 and Karnal Local. The basmati maintainers identified were Basmati 370, Pusa basmati 1, P615‐K‐167‐13 and P1173‐4‐1. The frequency of restorers obtained was higher for the non‐aromatic than the aromatic basmati type. The performance of restorers varied with cytoplasmic male‐sterile (CMS) line, location and season of testing. The differential ability to restore fertility in the CMS lines that have the wild abortive (WA) cytosterile system could result from different nuclear backgrounds of the CMS lines. These restorers and maintainers possess acceptable grain dimensions, a desirable degree of aroma, volume expansion through linear kernel elongation and cooking quality characteristics of basmati rice. These genotypes will contribute to developing basmati hybrids and provide restorers and maintainers with acceptable key basmati quality characteristics.     

Inheritance and mapping of a restorer gene for the rapeseed cytoplasmic male sterile line 681A

A novel cytoplasmic male sterility‐fertility restoration system has been developed in rapeseed (Brassica napus). The cytoplasmic male sterile line 681A was derived from a spontaneous male sterile mutant in a newly released double‐low rapeseed cultivar ‘Xiangyou 13′. The restorer line 714R was identified in the interspecific progeny from a B. napus×B. juncea‐cross. Genetic analysis showed that fertility restoration for 681A cytoplasmic male sterility was controlled by a single dominant nuclear gene which might originate from B. juncea. The RAPD marker S1039_‐520 was found to be linked to the restorer gene in F₂ progeny of 681A × 714R with a recombination frequency of 5.45%.     

Genetic and histological characterization of a novel recessive genic male sterile line of <Emphasis Type="Italic">Brassica napus</Emphasis> derived from a cross with <Emphasis Type="Italic">Capsella bursa</Emphasis>-<Emphasis Type="Italic">pastoris</Emphasis>

In a previously made cross Brassica napus cv. Oro (2n = 38) × Capsella bursa-pastoris (2n = 4x = 32), one F₁ hybrid with 2n = 38 was totally male sterile. The hybrid contained no complete chromosomes from C. bursa-pastoris, but some specific AFLP (amplified fragment length polymorphism) bands of C. bursa-pastoris were detected. The hybrid was morphologically quite similar to ‘Oro’ except for smaller flowers with rudimentary stamens but normal pistils, and showed good seed-set after pollination by ‘Oro’ and other B. napus cultivars. The fertility segregation ratios (3:1, 1:1) in its progenies indicated that the male sterility was controlled by a single recessive gene. In the pollen mother cells of the male sterile hybrid, chromosome pairing and segregation were normal. Histological sectioning of its anthers showed that the tapetum was multiple layers and was hypertrophic from the stage of sporogenic cells, and that the tetrads were compressed by the vacuolated and disaggregated tapetum and no mature pollen grains were formed in anther sacs, thus resulting in male sterility. The possible mechanisms for the production of the male sterile hybrid and its potential in breeding are discussed.     

Identification of the Rf gene conferring fertility restoration of the CMS Dian-type 1 in rice by using simple sequence repeat markers and advanced inbred lines of restorer and maintainer

Cytoplasmic male sterility of Dian‐type 1 (CMS‐D1) was developed 30 years ago in Yunnan. A major gene conferring fertility restoration for the CMS‐D1 system was detected by microsatellite markers in advanced inbred lines consisting of 196 maintainers and 62 restorers developed in breeding programmes of hybrid rice involving the CMS‐D1 system. The gene was mapped between two simple sequence repeat markers, OSR33 and RM228, on chromosome 10, and was temporarily designated as Rf‐D1(t). The genetic distances of the gene to the two microsatellite markers were 3.4 and 5.0 cM, respectively. This linkage was confirmed by using an F2 population derived from a cross between a CMS‐D1 line and a restorer. This study also demonstrated that using OSR33 was reliable and efficient for identification of restoring lines in hybrid rice breeding with the CMS‐D1 system.     

Production of a desirable Brassica oleracea CMS line using an alloplasmic B. rapa CMS line carrying Diplotaxis erucoides cytoplasm as a bridge plant

In Brassica oleracea, production of F₁ hybrid seeds mainly makes use of the improved Ogura cytoplasmic male sterile (CMS) line. However, reliance on one particular line is a risk, and it would be advantageous to develop other CMS lines. In this study, we transferred Diplotaxis erucoides cytoplasm to B. oleracea cultivars using an alloplasmic B. rapaCMS line as a bridge plant to avoid incompatibility between donor and recipient plants. The new B. oleraceaCMS lines, which were derived by four generations of backcrossing, had small rudimentary anthers with no pollen grain and showed complete male sterility. There was no functional defect in other floral organs, and the ability to receive normal pollen did not appear to be impaired. Moreover, the B. oleraceaCMS lines carrying D. erucoides cytoplasm had larger leaf areas and a normal plastochron. As a consequence, the B. oleraceaCMS lines carrying D. erucoides cytoplasm have the potential to be valuable alternatives for use in commercial B. oleracea hybrid seed production.     

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。