Male sterility in wheat : Male sterility in wheat UMESH KUMAR AK CHHABRA INTRODUCTION: INTRODUCTION Wheat ( Triticum aestivum ) is one of the world’s leading cereal crops. Wheat production in India has increased about 12 times from 6.4 million tones in 1950 to 80.5 million tones in 2009 (Anonymous, 2009). India ranks second in wheat production among wheat growing countries of the world preceded only by the China. Wheat production has increased nine folds in Haryana during last three decades (2008-09: 46 qtl /ha). Taxonomy: Taxonomy Division : Spermatophyta Sub-division : Angiospermae Class : Monocotyledonae Series : Glumaceae Family : Gramineae Genus : Triticum Species : aestivum Mode of Pollination: Mode of Pollination Normally self-pollinated crop. Chasmogamy is common. Cleistogamy is also present in few genotypes. Cross-pollination range from 0.5% to 1.0% . Main tiller flowers first and lateral tillers later in the order of their formation. Main Species of Wheat: Main Species of Wheat Species Genome Common name Triticum aestivum AABBDD bread wheat (2n=42) T.durum AABB macaroni wheat (2n=28) T.dicoccum AABB emmer wheat (2n=28) T.turgidum AABB rivit wheat (2n=28) T.compactum AABBDD club wheat (2n=42) T.sphaerococcum AABB dwarf wheat (2n=28) Varieties of wheat through pureline selection and pedigree selection : Varieties of wheat through pureline selection and pedigree selection Varieties through pureline selection :- NP 4, NP 6, NP 12, C 13, K 46, K 53, K 54, Pb 8, Pb 8A, Pb 9D & Pb 11 Varieties through pedigree selection :- NP 52, NP 80-5, NP 120, NP 150, NP 700, NP 800, K 65 & WL 711 Challenge of Increasing yield in wheat: Challenge of Increasing yield in wheat After the initial success of the green revolution, wheat yields have reached the plateau level. Since the scope for area expansion is very limited, we shall have to go for increase our production. In this endeavour , exploitation of heterosis in wheat. Although hybrid technology has paid rich dividends, successful exploitation of heterosis / hybrid vigour on commercial basis is still awaited in important crop like wheat. Hence the use of male sterility for hybrid seed production is one of the best alternative for increasing yield to meet the need of future generation. History of male sterility in wheat: History of male sterility in wheat Kihara (1951)was the first to reported cytoplasmic genic male sterility in wheat. Later on, Wilson and Ross(1962)establish the existance of useable male sterlity in wheat from the interaction of common wheat nucleus with Triticum timopheevi cytoplasm. Ghiasi and Lucken (1982)also concluded that Aegilops speltoides cytoplasm can be used interchangeably with that of Triticum timopheevi asan sorses of male sterlity in wheat. MALE STERILE WHEAT Sources of Male sterility in wheat: Sources of Male sterility in wheat Cytoplasm of following different species of wheat is generally used for creating male sterility Triticum timopheevi and its derivatives T.timonovum,T.timococcom and T.zhukovskyi Aegilops comoso Aegilops spltoides Aegilops columanaris Aegilops recta Triticum timopheevi T.zhukovskyi Aegilops comoso Aegilops spltoides Aegilops comoso : Aegilops comoso Sources of Male sterility in wheat Aegilops spltoides : Aegilops spltoides Goat Grass Sources of Male sterility in wheat Triticum timopheevi : Triticum timopheevi Sources of Male sterility in wheat T.zhukovskyi : T.zhukovskyi Sources of Male sterility in wheat Aegilops columanaris : Aegilops columanaris Sources of Male sterility in wheat Why Triticum timopheevi is most widely used as a source of male sterility : Why Triticum timopheevi is most widely used as a source of male sterility Several important factors/genes of fertility restoration for CMS in Triticum timopheevi have been found as compared to its derivatives and other species(in these in very less no.) . And out of these several fertility factors/genes presence of only three genes will be adequate for complete fertility restoration in most environment and genetic back grounds. Types of male sterility in wheat: Types of male sterility in wheat In wheat generally CGMS system of male sterility is used to produce hybrid wheat. Though Chemical Hybridizing Agents(CHA), Chromosomal male sterility( ChMS ) and Nuclear male sterility(NMS) are also used but not at broad level. Cytoplasmic male sterility in wheat: Cytoplasmic male sterility in wheat This type of male sterility is determined by the cytoplasmic genome. Since the cytoplasm of a zygote comes primarily from egg cell, the progeny of male sterile plants would always be male sterile. CMS(from Triticum timopheevi ) may be transferred easily to a given strain of wheat ( Triticum aestivum ) often called line B or maintainer line, by using that strain as a pollinator ( Triticum aestivum as a recurrent parent) in the successive generations of a backcross. Male sterile line is known as A line. A B R Types of cytoplasmic male sterility: Types of cytoplasmic male sterility Y A – Type cytoplasmic male sterility Photoperiod- sensitive cytoplasmic male sterility(PCMS) Photoperiod- sensitive cytoplasmic male sterility(PCMS): Photoperiod- sensitive cytoplasmic male sterility(PCMS) It is caused by Aegilops crassa cytoplasm under a long day photoperiod (greater than or equal to 15 hours) has been proposed as a new means of producing hybrid varieties in common wheat. The PCMS line is maintained by self- pollination under short day conditions and hybrid seeds can be produced through out-crossing of PCMS lines with a pollinator under long day conditions. Murai,K (2002) Aegilops crassa YA-type cytoplasmic male sterility: YA-type cytoplasmic male sterility YA-type cytoplasmic male sterility :-it is developed by institute of genetics and developmental biology , Chinese Academy of Science. In YA-type CMS system 2 pairs of independent majors genes and some minor genes were found to be able to cause fertility restoration. As a new CMS system, the YA-type CMS line is of potential value for hybrid wheat breeding. Liu,C.G . et al.(2006) Chromosomal male sterility system in wheat (ChMS) : Chromosomal male sterility system in wheat ( ChMS ) This system involves a recessive male sterility gene (ms)on a wheat chromosome and male fertility gene (Ms)on a homologous alien chromosome. The three line involved in this system i.e. X,Y&Z are homologous for ms and contain 2,1 & 0 doses of alien chromosome respectively. Ms operates on sporophytic tissue in such a way that Y lines produces 21 chromosome and 22 chromosmes gametes, X lines produce 22 chromosomes pollen only and are relatively true breeding. Z lines , derived from segregating Y lines, are male sterile. Advantages of ChMS over CMS type sterility : Advantages of ChMS over CMS type sterility Any deficiency in fertility restoration affects only the stage of hybrid-seed production. Hybrid seed production can be performed in an environment other than that in which the crop is produced. The male parent in the chromosomal system contains no special fertility restoring genes similar to those in the cytoplasmic system. Male parents for the stage of hybrid seed production can be developed which possess different resistance genes for a particularly pathogens. Hybrid are able to contain translocated alien sagements bearing diseases resistant genes. Fertility restoration system in wheat : Fertility restoration system in wheat Fertility restoration system in wheat is a very complex process involving many genes. It also differ in species in wheat. Foe study this system we have to study its genetics in detail which will be explained next slides. Some sources of fertility restoration in wheat: Some sources of fertility restoration in wheat Indian varieties like NP- 839, NP- 883, NP-880 derived from Kalyansona , NP 80-5, NP 120, NP 150, NP 700, K 53, K 54, Pb 8, Pb 8A, Pb 9D & Pb 11 and some foreign varieties like Primepi , Palmaress and Marquis2 etc. are vary good source of fertility restoration. Instead of these other partial restores have been observed among the Indian varieties. Swaminathan , M.S. , 1972 Genetic characteristics of fertility restoration system : Genetic characteristics of fertility restoration system In wheat fertility restoration system will follow the incomplete dominance with the epistatic action of single recessive allele with the ratio 9:3 :4 in support of this NettevicE.D ., Naumov,A.A ., conduct an experiment with the crossing of Primepi , Palmaress , Triticum timopheevii X Marquis 2 and T. spelta var. duhamelianum with four different male sterile lines of spring bread wheat, Primepi showed the highest restore capacity (80%) while Palmaress and T. spelta var. duhamelianum were partially effective (34- 38%) . Contd……….: Contd ………. In the F2 there was a continuous gradation from completely fertile to completely sterile forms. The number of male sterile plants varied from 22 to 34 % and of fertile forms from 6 to 21 %. In four out of 7 populations the segregation ratios were 9 partially fertile : 3 sterile : 4 fertile , by two incompletely dominant genes with the epistatic action of a single recessive alleles. Inheritance and chromosomal location of fertility restoring genes: Inheritance and chromosomal location of fertility restoring genes Chromosomal location and inheritance of the fertility restoring genes will be easily detected by using different markers like RFLP (Restriction fragmented Length Polymorphism). ISSR (Inter Simple Sequence Repeat Polymorphism). RAPD ( Randomly Amplified Polymorphism Detection). Contd………: Contd ……… Primer RAPD of (OPK18450) and primerof ISSR (UBC-845800) markers were employed to map the major restoring gene in a variety LK783. maintainer and restorer DNA pools were established using the extreme sterile and fertile plants among KJ5418A/911289/LK783 F1 population respectively. Linkage analysis showed that OPK 18450 and UBC -845800 were linked to the restoring gene in LK783. the marker of UBC 845800 was located on chromosomes IBS where the fertility restoring gene will be present. Liu,B.S . et.al.(2002) Comparison of FR system in two wheat varieties: Comparison of FR system in two wheat varieties Characters for comparison Norin 61 Chinese Spring Genes Rf Rfd1 Type of genes Multiple fertility-restoring genes Single dominant major genes Location of gene on chromosomes Chromosome no. 4A,1D,3D and 5D(at least these four) Chromosome no. 7B Degree of fertility restoration high low Conclusion : Conclusion As we know today is the staggered condition in wheat yield and a wide range of male sterility and fertility restorer are exist in wheat so if we are able to find good species in wheat with better genetic base and genes for fertility restoration then we hopes to increase the yield by hybrid seed production.