浅议水稻亚种间杂种不育性的遗传基础

水稻亚种间杂种不育性是一个普遍现象,但其遗传基础复杂。本文对这种亚种间杂种不育性的类型和表现,特别是前人推导两种解释杂种F1不育性遗传模型的研究方法、优越性及局限性进行了综述与分析,从中可以看出在水稻亚种间杂种F1不育性遗传研究上已经取得了较大的进展,在一些问题上已取得了一定的共识,如这种不育性的表现,细胞质的影响,杂交F1的染色体配对行为等;而在雌雄配子败育的作用大小,不育基因位点数目及不同不育基因位点的遗传特点等方面尚不完全一致;因而水稻亚种间杂种F1不育性的遗传有待进一步的研究。 Abstract：Hybrid sterility in the F1 populations of wide crosses in rice is a common phenomenon but the inheritance of the sterility is complex. This paper summarized the type and expression of the hybrid sterility, analyzed the experimental ideas, inference methods and advantage as well as disadvantages of two main genetic models used to explain the hybrid sterility, and concluded that there remains a lot to be investigated on the genetics of the hybrid sterility, for example, the number and effects of male and female sterility genes, although much advance has been made.     

水稻亚种间杂种是否存在雌性不育？

水稻亚种间杂种不育性是一种普遍现象,但其遗传基础复杂。目前在亚种间杂种不育遗传上,不同研究的结论不尽一致,即使对亚种间杂种不育性主要表现为雄性不育还是雌性不育也存在争论。本对证明水稻亚种间杂种存在和不存在雌性不育的研究进行了综述与分析。从中可以看出无论是认为水稻亚种间杂种不育性表现为雄性不育还是雌性不育的结论都有一定的片面性,尤其是Sano证明基因座S－5不存在的研究存在较大的缺陷。因此,水稻亚种间杂种雌雄配子败育对小穗育性影响的大小有待进一步研究。     

植物细胞核雄性不育的分子基础

植物细胞核雄性育性相关基因克隆,使我们对细胞核雄性育性的了解不仅局限于遗传分析和细胞学水平,而且对细胞核不育的分子基础,以及细胞核不育的分子机理也有了一定的了解。本文旨在对细胞核雄性不育相关研究的进展情况进行简要综述。 Abstract:With the cloning of nuclear male fertility genes,learning of nuclear male fertility not only limited in genetic analysis and cell biology,but also advanced in molecular basis of male nuclear sterility and postulated in possible mechanisms of nuclear male sterility.The objectives of this paper are to review the related progress of plant nuclear male sterility.     

小麦雄性不育遗传及基因定位研究进展

雄性不育的研究对于杂种优势的利用具有重要意义。本文综述了小麦雄性不育遗传及基因定位研究进展,介绍了小麦雄性不育的基因工程,对小麦雄性不育的应用进行了讨论。 Abstract:The study of plant male sterility plays an important role on utilization of heterosis.This paper reviews the current status of the studies of the heredity and mapping of the male sterile genes in wheat and the gene engineering of wheat male sterility.The application of male sterility in wheat breeding is discussed.     

MS1 is essential for male fertility by regulating the microsporocyte cell plate expansion in soybean

Male sterility is an essential trait in hybrid seed production, especially for monoclinous and autogamous food crops. Soybean male-sterile ms1 mutant has been known for more than 50 years and could be instrumental in making hybrid seeds. However, the gene responsible for the male-sterile phenotype has remained unknown. Here, we report the map-based cloning and characterization of the MS1 gene in soybean. MS1 encodes a kinesin protein and localizes to the nucleus, where it is required for the male meiotic cytokinesis after telophase Ⅱ. We further substantiated that MS1 colocalizes with microtubules and is essential for cell plate formation in soybean male gametogenesis through immunostaining. Both ms1 and CRISPR/Cas9 knockout mutants show complete male sterility but are otherwise phenotypically normal, making them perfect tools for producing hybrid seeds.The identification of MS1 has the practical potential for assembling the sterility system and speeding up hybrid soybean breeding.     

Development of the “Third-Generation” Hybrid Rice in China

Rice is a major cereal crop for China. The development of the ‘‘three-line" hybrid rice system based on cytoplasmic male sterility in the 1970 s(first-generation) and the ‘‘two-line" hybrid rice system based on photoperiod-and thermo-sensitive genic male-sterile lines(second-generation)in the 1980 s has contributed significantly to rice yield increase and food security in China. Here we describe the development and implementation of the ‘‘third-generation" hybrid rice breeding system that is based on a transgenic approach to propagate and utilize stable recessive nuclear male sterile lines, and as such, the male sterile line and hybrid rice produced using such a system is nontransgenic. Such a system should overcome the intrinsic problems of the ‘‘first-generation" and‘‘second-generation" hybrid rice systems and hold great promise to further boost production of hybrid rice and other crops.     

Understanding the genetic and molecular constitutions of heterosis for developing hybrid rice

The wide adoption of hybrid rice has greatly increased rice yield in the last several decades. The utilization of heterosis facilitated by male sterility has been a common strategy for hybrid rice development. Here, we summarize our efforts in the genetic and molecular understanding of heterosis and male sterility together with the related progress from other research groups. Analyses of F1 diallel crosses show that strong heterosis widely exists in hybrids of diverse germplasms, and inter-subsp...     

An epi-allele of SMS causes Sanming dominant genic male sterility in rice

Male sterility is an important trait in rice for hybrid rice(Oryza sativa) breeding. However, the factors involved in dominant male sterility are largely unknown. Here, we identified a gene from Sanming dominant genic male sterile rice, named Sanming dominant male sterility(SMS), and reported that an epi-allele of this locus contributes to male sterility. Segregation analysis attributed dominant male sterility to a single locus, SMS, which we characterized using a male-sterile near isogenic line...     

水稻广亲和性遗传的再研究

水稻广亲和基因的利用是克服亚种间杂种不育性的重要途径。但在广亲和性的遗传上不同研究者的结论不尽一致。以3种有广亲和品种参加的三交组合为研究材料,研究了品种Ketan Nangka的广亲和性遗传。结果表明水稻亚种杂交F1同时存在着雄性不育和雌性不育,但雄性不育对小穗育性的作用大小因组合而异;无论是在雄性不育位点还是雄性不育位点上,Ketan Nangka均具有相对应的中性基因（广亲和基因）;广亲和性的遗传特点与所用的籼粳测验品种间的杂种不育性密切相关;S－5位点的广亲和基因遗传符合单位点孢子体－配子体互作模型。     

Structural and Expressional Variation Analyses of Mitochondrial Genomes Reveal Candidate Transcripts for the SV Cytoplasmic Male Sterility in Wheat (Triticum aestivum L.)

Common wheat (Triticum aestivum L.) is one of the most important crops,and intra-specific wheat hybrids have obvious heterosis in yield and protein quality.Therefore,utilization of hybrid wheat varieties offers an effective way to increase yield and nutrition.Cytoplasmic male sterility (CMS) systems are a useful genetic tool for hybrid crop breeding,and are ideal models for studying the genetic interaction and cooperative function of mitochondrial and nuclear genomes in plants (Schnable and Wise,1998;Hanson and Bentolila,2004).The breeding of hybrid wheat using male sterility caused by the cytoplasm of T.timopheevii has been studied since the early 1960's.But it is unsuccessful because there are some deficiencies in the practical application of this cytoplasm,including limited restoration resources,thin seeds,pre-harvest sprouting and lower germination rate (Wilson and Ross,1962).The Sv type of cytoplasmic male sterility (CMS-Sv) in wheat is general accessions for four types of CMS lines that were derived from four Aegilops species:Ae.kotschyi,Ae.variabilis,Ae.ventricosa,and Ae.bicornis.Based on the observation of alloplasmic lines produced in all possible combinations between 12 wheat nuclear genotypes and 47 cytoplasms of two related genera,Triticum (wheat) and Aegilops,Ogihara and Tsunewaki (1988) concluded that the D2-cytoplasm of Ae.crassa and its relatives,N-cytoplasm of Ae.uniaristata,and SV-cytoplasm of Ae.kotschyi and its relatives might be used as the alternative male sterile cytoplasm to replace the T.timopheevii cytoplasm for hybrid wheat breeding.Ikeguchi et al.(1999) proposed that spring-type hybrid wheat may be bred by combination of the 1BL-1RS chromosome and Ae.kotschyi cytoplasm with a new fertility-restorer gene discovered in a wheat variety Kitamiharu 48.Zhang et al.(1996) also proposed the use of CMS-Sv lines as the most effective male sterile cytoplasm.     

CRISPR/Cas9-mediated disruption of TaNP1 genes results in complete male sterility in bread wheat

Male sterile genes and mutants are valuable resources in hybrid seed production for monoclinous crops.High genetic redundancy due to allohexaploidy makes it difficult to obtain the nuclear recessive male sterile mutants through spontaneous mutation or chemical or physical mutagenesis methods in wheat.The emerging effective genome editing tool,CRISPR/Cas9 system,makes it possible to achieve simultaneous mutagenesis in multiple homoeoalleles.To improve the genome modification efficiency of the CRISPR/Cas9 system in wheat,we compared four different RNA polymerase(Pol) Ⅲ promoters(TaU3 p,TaU6 p,OsU3 p,and OsU6 p) and three types of sgRNA scaffold in the protoplast system.We show that the TaU3 promoter-driven optimized sgRNA scaffold was most effective.The optimized CRISPR/Cas9 system was used to edit three TaNP1 homoeoalleles,whose orthologs,OsNP1 in rice and ZmIPE1 in maize,encode a putative glucose-methanol-choline oxidoreductase and are required for male sterility.Triple homozygous mutations in TaNP1 genes result in complete male sterility.We further demonstrated that anyone wild-type copy of the three TaNP1 genes is sufficient for maintenance of male fertility.Taken together,this study provides an optimized CRISPR/Cas9 vector for wheat genome editing and a complete male sterile mutant for development of a commercially viable hybrid wheat seed production system.     

A straight-forward seed production technology system for foxtail millet (Setaria italica)

For autogamous crops, a precondition for using heterosis is to produce sufficient pure male-sterile female parents that can be used to produce hybrid seeds. To date, cytoplasmic male sterility(CMS)and environment-sensitive genic male sterility(EGMS) have been used commercially to exploit heterosis for autogamous species. However, neither CMS nor EGMS has been established for foxtail millet(Setaria italica). Here, we report on the establishment and application of a seed production technology(SPT)...     

A Comparison Studies on Ultrastructure and Calcium Distribution in Fertile and Sterile Anthers of a Genic Male-sterile Rapeseed （Brassica napus L.）

It‘s common understanding that plant male sterility is closely related to cell ultrastructure or cell microstructure,plant physiological and biochemical metabolism during the generation and development of anthers. The materials used for the study were fertile and sterile anthers in various stages of a genic male-sterile rapeseed     

北京地区蒿柳的开花物候期及单花序开放过程中花粉活力和柱头可授性变化

Flowering phenology and flowering dynamics of female and male inflorescences of Salix viminalis Linn. in Beijing were observed in 2015 and 2016, and changes in pollen activity and stigma receptivity were also investigated. The results show that early flowering stage of S. viminalis in Beijing is happened in early?March, flowering period is 11-18 d, and flowering pattern is the first opening type of male flower. Flowering period of single inflorescence in male and female plants is 10-15 d and 8-10 d, respectively, which can be divided into five stages:emerging color stage, initial flowering stage, half flowering stage, full flowering stage and withered stage. Flowering date of male plant is earlier about 3-4 d than that of female plant. However, the difference of full flowering stage between male and female plants is only 1 d. Pollen germination rate and stigma receptivity show a trend of firstly increasing then decreasing during blossom process. Pollen germination rate reaches the highest of 72% at full flowering stage, and stigma receptivity is more than 90% at half and full flowering stages. Therefore, it is suggested that pollen collection and pollination in mid?March can improve success rate of cross breeding of S. viminalis.     

Characterization and Use of Male Sterility in Hybrid Rice Breeding

The hybrid rice （Oryza sativa L.） breeding that was Initiated In China in the 1970s led to a great improvement in rice productivity. In general, It increases the grain yield by over 20% to the inbred rice varieties, and now hybrid rice has been widely introduced into Africa, Southern Asia and America. These hybrid varieties are generated through either three-line hybrid and two-line hybrid systems; the former is derived from cytoplasmic male sterility （CMS） and the latter derived from genlc male sterility （GMS）. There are three major types of CMS （HL, BT and WA） and two types of GMS （photoperlod-sensitlve （PGMS） and temperature-sensitive （TGMS））. The BT- and HL-type CMS genes are characterized as orf79 and orfH79, which are chimeric toxic genes derived from mltochondrial rearrangement. Rf3 for CMS-WA Is located on chromosome 1, while Rf1, Rf4, Rf5 and Rf6 correspond to CMS-BT, CMSoWA and CMS- HL, located on chromosome 10. The Rfl gene for BT-CMS has been cloned recently, and encodes a mltochondriatargeted PPR protein. PGMS Is thought to be controlled by two recessive loci on chromosomes 7 and 12, whereas nine recessive alleles have been identified for TGMS and mapped on different chromosomes. Attention Is still urgently needed to resolve the molecular complexity of male sterility to assist rice breeding.     

Nonlinear Phenomena Conveying Body Size Information and Improving Attractiveness of the Courtship Calls in the Males of Odorrana tormota

Nonlinear phenomena are commonly shown in the vocalization of animals and exerts different adaptive functions.Although some studies have pointed out that nonlinear phenomena can enhance the individual identification of male Odorrana tormota,whether the nonlinear phenomena play a specific role in the sexual selection of O.tormota remain unclear.Here we presented evidence that there was a significant negative correlation(Pearson:n=30,r=0.65,P<0.001)between the nonlinear phenomena content and snout-vent length in the male O.tormota,and two-choice amplexus experiments showed that female O.tormota preferred male with smaller body size containing higher nonlinear phenomena content in its calls.Phonotaxis experiments also revealed that females preferred calls with higher nonlinear phenomena content.Additionally,compared to the calls with lower nonlinear phenomena content and higher fundamental frequency,there was shorter response time in phonotactic behaviour of female induced by the calls with higher nonlinear phenomena content and lower fundamental frequency.We argue that the nonlinear phenomena content in the calls of male O.tormota can convey its body size information and may provide important clues for female frogs in darkened surroundings to identify males’body size during mate choice,meanwhile,higher nonlinear phenomena content in males’calls may increase the attractiveness of males to females.The results of this study provide confirmation that,for O.tormota,nonlinear phenomena have specific function in mate choice.     

圈养小熊猫繁殖行为变化及繁殖行为对策

In order to investigate the change of reproductive behaviors and understand reproductive strategies of both male and female red pandas, one-year behavioral observation was conducted through the focal sampling method in the Chengdu Research Base of Giant Panda Breeding from December 1999 to November 2000. Our results indicated that reproductive behaviors showed significant differences between the estrous and non-estrous seasons. Frequencies of the rubbing anogenital, sniffing and licking marking were much higher in estrus than in non-estrus. Bleating only appeared in the estrus and can be regarded as an estrous indicator.The result also demonstrated that both male and females applied different reproductive behavioral strategies. Frequencies of activity, rubbing anogenital, licking and sniffing marking, and bleat were much higher in the male than in the female. However, those of resting and investigating were much lower in the male than in the female. This indicated that the male was more active than the female during the estrus and might imply that the male acts mainly as an estrous message sender, and the female as a message receiver in the estrous season.     

Long non-coding RNAs play an important role in regulating photoperiod-and temperature-sensitive male sterility in rice

正Rice(Oryza sativa L.)is a major food crop for more than half of the world’s population.Therefore,increasing rice production is of great importance.The successful development of hybrid rice in the 1970s was an important achievement for increasing yield potential,since hybrid rice varieties produce higher yields than inbred varieties(Cheng et al.,2007).In plants,male sterility refers to the inability of producing dehiscent anthers and functional pollen(Chen and Liu,2014).The