The more knowledge about heterotic loci is a pre-requisite for enhancing grain yield potential in distant crosses

Paper Details

Research Paper 01/11/2014
Views (147) Download (2)
current_issue_feature_image
publication_file

The more knowledge about heterotic loci is a pre-requisite for enhancing grain yield potential in distant crosses

Adedze Yawo Mawunyo Nevame, Reza Mohammad Emon, Tondi Yacouba Nassirou,Gandeka Mamadou, Aboubakar Demba Samoura
Int. J. Agron. Agri. Res.5( 5), 200-215, November 2014.
Certificate: IJAAR 2014 [Generate Certificate]

Abstract

Overcoming reproductive barrier is one of key indicators for exploiting heterosis in distant crosses. This paper reports the current studies on the genes/QTLs controlling hybrid sterility as well as the heterosis in distant crosses. To avoid hybrid sterility problem in distant crosses of rice, the use of wide compatibility gene and development of partial hybrid rice were adopted consecutively. Though these efforts made, rice scientists were still concerned about hybrid sterility occurrence, which hamper the exploitation of strong grain yield heterosis in rice. But a better understanding of the genetic factors that govern hybrid sterility and heterosis could facilitate the introgression of useful genes/QTLs in rice. In this review, 57 inter-subspecific genes/QTLs and 18 interspecific genes/QTLs were reported to cause hybrid sterility in distant crosses. On other hand, a total of 33 stable Heterotic loci (HLs) were also found to be associated with yield-related traits. The cross-check observation showed 11 genes/QTLs to be implicated in distant hybrid sterility irrespective of the crosses made. Surprisingly, the marker RM236 was identified to be closed simultaneously to the chromosome region affecting hybrid sterility and heterosis. However, many other stable heterotic loci with positive effect on yield-related traits were isolated in rice. Therefore, we propose the pyramiding of these heterotic loci (HL) via marker assisted selection (MAS) into one adaptable rice variety as an efficient approach to develop new rice variety with higher grain yield potential.

VIEWS 3

Adedze YMN, Efisue AA, Zhang SS, Samoura D, Huang F, He WC, Xie GS, Jin DM. 2012. Identification of interspecific grain yield heterosis between two cultivated rice species Oryza sativa L. and Oryza glaberrima Steud. Australian Journal of crop Science 6, 1558–1564.

Akhter Z, Shamsuddin AKM, Rohman MM, Shalim Uddin M, Mohi-Ud-din M, Alam AKMM. 2008. Studies on heterosis for yield and yield components in wheat. Journal of Biological Sciences 3, 892 – 897.

Aluko GK. 2003. Genetic mapping of agronomic traits from the interspecific cross of Oryza sativa (L.) and Oryza glaberrima (Steud). PhD Dissertation, 127 p.

Ben-Israel I, Kilian B, Nida H, Fridman E. 2012. Heterotic Trait Locus (HTL) Mapping Identifies Intra-Locus Interactions That Underlie Reproductive Hybrid Vigor in Sorghum bicolor. Plosone 7, e38993 http://dx.doi.org/10.1371/journal.pone .0038993.

Bimpong IK, Carpena AK, Mendioro MS, Fernandez JR, Ramos J, Reversat G, Brar DS. 2010. Evaluation of Oryza sativa x Oryza glaberrima derived progenies for resistance to rootknot nematode and identification of introgressed alien chromosome segments using SSR markers. African Journal of Biotechnology 9, 3988 – 3997.

Bimpong IK, Chin JH, Ramos J, Koh HJ. 2011. Application of subspecies- specific marker system identified from Oryza sativa to Oryza glaberrima accessions and Oryza sativa x Oryza glaberrima F1 interspecific progenies. International Journal of Genetics and Molecular Biology 3, 7– 24.

Brandle JE, McVetty PBE. 1990. Geographic diversity, parental selection, and heterosis in oilseed rape. Canadian Journal of Plant Science 70, 935- 940.

Chen J, Jiang L, Wang C. 2006. Mapping of loci for pollen sterility of indica-japonica hybrids in rice (Oryza sativa L.). Acta Agronomica Sinica 32, 515– 521.

Chen JJ, Ding JH, Ouyang YD, Du HY, Yang JY, Cheng K, Zhao J, Qiu SQ, Zhang XL, Yao JL, Liu KD, Wang L, Xu CG, Li XH, Xue YB, Xia M, Ji Q, Lu JF, Xu ML, Zhang QF. 2008. A triallelic system of S5 is a major regulator of the reproductive barrier and compatibility of indica-japonica hybrids in rice. Proceedings of the National Academy of Sciences 105, 11436–11441.

Cheng SH, Li YC, Jie YZ, Shen GC, Xiao DZ, Ye YF, De FZ, Shao KM. 2007. Super Hybrid Rice Breeding in China: Achievements and Prospects. Journal of Integrative Plant Biology 49, 805−810.

Doi K, Taguchi K, Yoshimura A. 1999. RFLP mapping of S20 and S21 for F1 semi-sterility found in backcross progeny of Oryza sativa and O. glaberrima. Rice Genetics Newsletter 16, 65–68.

Efisue AA, Tongoona P, Derera J. 2009b. Screening Early-Generation Progenies of Interspecific Rice Genotypes for Drought-Stress Tolerance during Vegetative Phase. Journal of Crop Improvement 23, 174 – 193.

Efisue AA, Tongoona P, Derera J, Ubi EB, Oselebe OH. 2009a. Genetics of Morpho-Physiological Traits in Segregating Populations of Interspecific Hybrid Rice under Stress and Non-Stress Conditions. Journal of Crop Improvement 23, 383–401.

Feng XM, Huang J, Qi HH, Huang YQ, Zhu LY, Zhao YF, Zheng Q, Li WZ, Yue B. 2012. Identification of heteroticloci forseven yield and yield-related traits in maize witha set of introgression lines. Australian Journal of Crop Science 6, 1661– 1665.

Frascaroli E, Cane MA, Pe`ME, Pea G, Landi P. 2012.Characterization of heterotic quantitative trait loci in maize by evaluation of near-isogenic lines and their crosses at two competition levels. Theoretical and Applied Genetics 124, 35–47.

Garcia AAF, Wang SC, Melchinger AE, Zeng ZB. 2008. Quantitative Trait Loci Mapping and The Genetic Basis of Heterosis in Maize and Rice. Genetics 180, 1707–1724.

Guo X, Guo YP, Ma J, Wang F, Sun MZ, Gui LJ, Zhou JJ, Song XL, Sun XZ, Zhang TZ. 2013.Mapping Heterotic Loci for Yield and Agronomic Traits Using Chromosome Segment Introgression Lines in Cotton. Journal of Integrative Plant Biology 55, 759–774.

He GM, Luo XJ, Tian F, Li KG, Zhu ZF, Su W, Qian XY, Fu YC, Wang XK, Sun CQ. 2006. Haplotype variation in structure and expression of a gene cluster associated with a quantitative trait locus for improved yield in rice. Genome Research 16, 618– 626.

He YX, Zheng TQ, Hao XB, Wang LF, Gao YM, Hua ZT, Zhai HQ, Xu JL, Xu ZJ, Zhu LH, Li ZK. 2010. Yield performances of japonica introgression lines selected for drought tolerance in a BC breeding program. Plant breeding 129, 167–175.

Heuer S, Miezan KM. 2003. Assessing hybrid sterility in Oryza glaberrima x O. sativa hybrid progenies by PCR marker analysis and crossing with wide compatibility varieties. Theoretical and Applied Genetics 107, 902–909.

Hirano H, Sano Y, Hirai A, Sasaki T. 2008. Genetics of Speciation in Rice. In: Hirano H Y, Hirai A, Sano Y, et al., eds. Rice Biology in the Genomics Era. Berlin Heidelberg: Springer 247–259.

Hiroko M, Kokichi H, Hiko-Ichi O. 1962. Comparison between two cultivated rice species O.sativa L and O.glaberrima STEUD. Japanese Journal of Breeding 12, 17– 29.

Hu F, Xu P, Deng X, Zhou J, Li J, Tao D. 2004. Molecular mapping of a new pollen killer gene S29(t) on chromosome 2 in Oryza glaberrima. Rice Genetics Newsletter 21, 31–33.

Hu FY, Xu P, Deng XN, Zhou JW, Li J, Tao DY. 2006. Molecular mapping of a pollen killer gene S29(t) in Oryza glaberrima and co-linear analysis with S22 in O. glumaepatula. Euphytica 151, 273– 278.

Hu, FY, Xu P, Deng XN, Zhou JW, Li J, Tao DY. 2006. Molecular mapping of a pollen killer gene S29 (t) in Oryza glaberrima and co-linear analysis with S22 in O. glumaepatula. Euphytica. 151: 273– 278.

Hua JP, Xing YZ, Wu WR, Xu CG, Sun XL, Yu SB, Zhang QF. 2002. Single-locus heterotic effects and dominance by dominance interaction can adequately explain the genetic basis of heterosis in an elite rice hybrid. Proceedings of the National Academy of Sciences 100, 2574–2579.

Ikeda R, Yoshimi S, Inouss AA. 2009. Seed fertility of F1 hybrids between upland rice NERICA cultivars and Oryza sativa L. or O.glaberrima Steud. Breeding Science 59, 27 – 35.

Ikehashi H, Araki H. 1986.Genetics of F1 sterility in remote crosses of rice. Genetics 189, 1083–1092.

Jagoz B. 2011.The relationship between heterosis and genetics distance based on RAPD and AFLP markers in carrot. Plant breeding 30, 574 – 579.

Jaikishan I, Rajendrakumar P, Ramesha MS, Viraktamath Bc, Balachandran SM, Neeraja CN, Sujatha K, Srinivasa RK, Natarajkumar, P, Hari Y, Sakthivel Ramaprasad AS, Sundaram RM. 2010. Prediction of heterosis for grain yield in rice using key informative EST-SSR. Plant breeding 129, 108– 111.

Jiang TB, Li RH, Sun CQ, Wang XK. 2002. Utilization of diverse rice ecotypes in heterosis breeding. Breeding science 52, 107-113.

Jones MP, Dingkuhn M, Aluko GK, Semon M. 1997. Interspecific Oryza sativa L. X O. glaberrima Steud. progenies in upland rice improvement. Euphytica 92, 237–246.

Jones MP, Dingkuhn M, Johnson DE, Sow A.1998.Growth and yield potential of Oryza sativa and O. glaberrima upland rice cultivars and their interspecific progenies. Field Crop Research 57, 57– 69.

Koide Y, Ikenaga M, Sawamura N, Nishimoto DK , Matsubara KK , Onishi KM , Kanazawa A, Sano Y. 2008.The evolution of sex-independent transmission ratio distortion involving multiple allelic interactions at a single locus in rice. Genetics 180, 409–420.

Koide YA, Onishi K, Nishimoto D, Baruah R, Kanazawa A, Sano Y. 2008. Sex-independent transmission ratio distortion system responsible for reproductive barriers between Asian and African rice species. New Phytologist 179, 888–900.

Krishnamurthy SL, Mohan RA, Madhavi RK, Ramesh S, Hittalmani S, Rao MG. 2013. Limits of parental divergence for the occurrence of heterosis through morphological and AFLP marker in chilli (Capsicum annuumL.). Current science 6, 25.

Kubo T, Eguchi M, Yoshimura A. 2000.A new gene for F1 pollen sterility in Japonica/Indica cross of rice. Rice Genetic Newsletter 17, 63–69.

Kubo T, Yamagata Y, Eguchi M, Yoshimura A. .2008. A novel epistatic interaction at two loci causing hybrid male sterility in an inter-subspecific cross of rice (Oryza sativa L.). Genes and Genetic Systems 83, 443–453.

Kubo T, Yoshimura A. 2001. Linkage analysis of an F1 sterility gene in Japonica/Indica cross of rice. Rice Genetic Newsletter 18, 52–53.

Kubo T, Yoshimura A, Kurata N. 2011. Hybrid Male Sterility in Rice Is Due to Epistatic Interactions with a Pollen Killer Locus. Genetics 189, 1083–1092.

Kubo Yamagata T, Eguchi Y, Yoshimura M. 2008. AA novel epistatic interaction at two loci causing hybrid male sterility in an inter-subspecific cross of rice (Oryza sativa L.). Genes and Genetic Systems 83: 443–453.

Li D, Chen L, Jiang L, Zhu SS , Zhao ZG, Liu SJ, Su N , Zhai HQ , Ikehashi H , Wan JM. 2007. Fine mapping of S32(t), a new gene causing hybrid embryo sac sterility in a Chinese landrace rice (Oryza sativa L.). Theoretical and Applied Genetics 114, 515―524.

Li DJ, Sun CQ, Fu YC, Li C, Zhu ZF, Chen L, Cai HW, Wang XK. 2002. Identification and mapping of genes for improving yield from Chinese common wild rice (O. rufipogon Griff.) using advanced backcross QTL analysis. Chinese Science Bulletin 18, 1533–1537.

Li F, Liu FH, Morinaga DZ. 2011. A new gene for hybrid sterility from a cross between Oryza sativa and O. glaberrima. Plant Breeding 130, 165-171.

Li J, Xu P1, Zhou JW, Hu FY, Deng XN, Chen ZW, Tao DY. 2011. Molecular Mapping of Sterility QTL qSS-3, qSS-6a and qSS-7 as Single Mendelian Factors via NIL strategy. Rice Science 18.

Li WT, Zeng RZ, Zhang ZM, Ding XH, Zhang GQ. 2006. Fine mapping of locus S-b for F1 pollen sterility in rice (Oryza sativa L.). Chinese Science Bulletin 51,675–680.

Li WT, Zeng RZ, Zhang ZM, Ding XH, Zhang GQ. 2008. Identification and fine mapping of S-d, a new locus conferring the partial pollen sterility of intersubspecific F1 hybrids in rice (Oryza sativa L.). Theoretical and Applied Genetics 116, 915–922.

Li ZK, Luo LJ, Mei HW, Shu QY, Tablen R, Zhong DB, Ying CS, Stansel JW, Khush GS, Paterson AH. 2001. Overdominant epistatic loci are the primary genetic basis of inbreeding depression and heterosis in rice. I. Biomass and grain yield, Genetics 158, 1737–1753.

Liu WM. 2012. Correlation and Path Analysis of Yield Traits on ‘Yongyou12’ Indica-japonica Intersubspecific Hybrid Rice. Nongxue Nongbao. 2, 1–4.

Long YM, Zhao LF, Niu BX, Su J, Wu H, Chen YL, Zhang QY, Guo JX, Zhuang CX, Mei MT, Xia JX, Wang L, Wu HB, Liu YG. 2008. Hybrid male sterility in rice controlled by interaction between divergent alleles of two adjacent genes. Proceedings of the National Academy of Sciences 105, 18871– 18876.

Lu YF, Ma RR, Wang XY, Li XN, Zhou HC, Zhang ZY, Hua GL. 2007. SSLP—Based SSR fingerprinting and indica/japonica Classification of Yongyou Series Hybrid. Rice Science 21, 443– 446.

Luo LJ, Li ZK, Mei HW, Shu QY Tablen R, Zhong DB, Ying CS, Stansel JW, Khush GS, Paterson AH. 2001. Overdominant epistatic loci are the primary genetic basis of inbreeding depression and heterosis in rice. II. Grain yield components. Genetics 158, 1755–1771.

Luo LJ, Mei H, Yu X, Wang Y, Zhong D, Ying C, Li Z, Paterson AH. 1999. Yield heterosis performance and their parental genetic diversity in rice. Rice Science 13, 6 – 10.

Luo XJ. 2006. Analysis of the heterotic loci between common wild rice (O. rufipogon Griff.) and cultivated rice (O. sativa L.) and fine-mapping the yield-enhancing QTL. Ph.D. degree thesis of China Agriculture University.

Luo XJ, Tian F, Fu YC, Yang JS, Sun CQ. 2009. Mapping QTL influencing panicle-related traits from Chinese common wild rice (Oryza rufipogon Griff.) using introgression lines. Plant Breeding 128, 559– 567.

Luo XJ, Wu S, Tian F, Xin XY, Zha XJ, Dong XX, Fu YC, Wang XK, Yang JS, Sun CQ. 2011. Identification of heterotic loci associated with yield-related traits in Chinese common wild rice (Oryza rufipogon Griff). Plant Science 181, 14–22.

Ma RR, Xu DH, Wang XY, Yu SM, Jin QY, Ouyang YN, Zhu LF. 2007. Heterosis on plant Morphology of Youyong6, an Indica-Japonica inter-subspecific super yielding hybrid rice. Rice Science 21, 281–286.

Marathi B, Guleria S, Mohapatra T, Parsad R, Mariappan N, Kurungara VK, Atwal SS, Prabhu KV, Singh NK, Singh AK. 2012. QTL analysis of novel genomic regions associated with

yield and yield related traits in new plant type based recombinant inbred lines of rice (Oryza sativa L.). BMC Plant Biolology 12, 137.

Matsubara K, Ando T, Mizubayashi T, Ito S, Yano M. 2007. Identification and linkage mapping of complementary recessive genes causing hybrid breakdown in an intraspecific rice cross. Theoretical and Applied Genetics 115, 179–186.

Moehring AJ. 2011. Heterozygosity and its unexpected correlations with hybrid sterility. Evolution 65, 2621–2630.

Ndjiondjop MN, Futakuchi K, Seck PA, Cisse F, Bocco R, Fatondji B. 2012. Morpho-agronomic evaluation of Oryza glaberrima accessions and interspecific Oryza sativa X Oryza glaberrima derived lines under drought conditions. African Journal of Agricultural Research 7, 2527– 2538.

Ndjiondjop MN, Semagn K, Sie M, Cissoko M, Fatondji B, Jones M. (2008). Molecular profiling of interspecific lowland rice populations derived from IR64 (Oryza sativa) and Tog5681 (Oryza glaberrima). African Journal of Biotechnology 7, 4219 – 4229.

Nuruzzaman M, Alam MF, Ahmed MG, Shohael AM, Biswas MK, Amin MR, Hossain MM. 2002. Studies on parental variability and heterosis in rice. Pakistan Journal of Biological Sciences 5, 1006 – 1009.

Oka HI. 1964. Considerations on the genetic basis of intervarietal sterility in Oryza sativa in Rice. Genetics and Cytogenetics, Island publishing house, Inc, Sta. Mesa P.O. Box 406. Manila, Philipines. 159–174 p.

Ouyang YD, Chen JJ, Ding JH Zhang QF. 2009. Advances in the understanding of inter-subspecific hybrid sterility and wide-compatibility in rice. Chinese Science Bulletin 54, 2332–2341.

Qiu SQ, Liu K, Jiang JX, Song X, Xu CG, Li XH, Zhang QF. 2005. Delimitation of the rice wide compatibility gene S5n to a 40-kb DNA fragment. Theoretical and Applied Genetics 111, 1080–1086.

Sano Y. 1983. A new gene controlling sterility in F1 hybrids of two cultivated rice species. Journal of Heredity 74, 435–439.

Sano Y. 1985. Identification of sterility genes introduced from Oryza glaberrima into O. sativa. Japanese Journal of Breeding 35, 202–203.

Sano Y. 1986. Sterility barriers between Oryza sativa and O. glaberrima. In: International Rice Research Institute-IRRI (ed.) Rice Genetics, IRRI, Manila, 109–118 p.

Sano Y. 1992.Genetic comparisons of chromosome 6 between wild and cultivated rice. Japanese Journal of Breeding 42, 561–572.

Sano Y. (1990) The genic nature of gamete eliminator in rice. Genetics 125, 183–191.

SanoY. 1994. Pollen-killer in rice. Japanese Journal of Breeding 44, 298.

Sarla N, Swamy BPM. 2005. Oryza glaberrima: A source of improvement of Oryza sativa.Current science 89, 955 – 963.

Sawamura N, Sano Y. 1996. Chromosomal location of gamete eliminator, S11(t), found in an Indica-Japonica hybrid. Rice Genetic Newsletter 13, 70–7.

Semagn K, Ndjiondjop MN, Lorieux M, Cissoko M, Jones M, Mccouch S. 2007. Molecular profiling of an interspecific rice population derived from a cross between WAB 56-104 (Oryza sativa) and CG 14 (Oryza glaberrima). African Journal of Biotechnology 6, 2014–2022.

Shen SQ, Xue QZ. 1996. Analysis of heterosis in Inter-subspecific hybrids F1 among different types of rice. Rice Science 10, 7 – 12.

Singh SP, Sundaram RM, Biradar SK, Ahmed MI, Viraktamath BC, Siddiq EA. 2006. Identification of simple sequence repeat markers for utilizing wide-compatibility genes in inter-subspecific hybrids in rice (Oryza sativa L.). Theoretical and Applied Genetics 113, 509―517.

Sobrizal Y, Matsuzaki Y, Sanchez PL, Ikeda K, Yoshimura A. 2000. Identification of a gene for male gamete abortion in backcross progeny of Oryza sativa and Oryza glumaepatula. Rice Genetics Newsletter 17, 59–61.

Sobrizal Y, Matsuzaki Y, Yoshimura A. 2001. Mapping of a gene for pollen semi-sterility on chromosome 8 of rice. Rice Genetics Newsletter 18, 59–61.

Sobrizal Y, Matsuzaki Y, Yoshimura A. 2002. Mapping of pollen semi-sterility gene, S28(t), on rice chromosome 4. Rice Genetics Newsletter 19, 80–81.

Song X, Qiu SQ, Xu CG, Li XH, Zhang QF. 2005. Genetic dissection of embryo sac fertility, pollen fertility, and their contributions to spikelet fertility of intersubspecific hybrids in rice. Theoretical and Applied Genetics 110, 205–211.

Swaminathan MS, Siddique EA, Sharma SD. 1972. Outlook for hybrid rice in India. International Rice Research Institute, P.O. Box 933 , Manila , Philippines. Rice breeding 609–613.

Taguchi K, Doi K, Yoshimura A. 1999. RFLP mapping of S19, a gene for F1 pollen sterility found in a cross between Oryza sativa and O. glaberrima. Rice Rice Genetic Newsletter 16, 70–71.

Taneichi T, Koide Y, Nishimoto D, Sano Y. 2005. Hybrid sterility gene S13 found in a distantly related rice species, O. longistaminata. Genes and Genetic Systems 80, 477.

Tang JH, Ma XQ, Teng WT, Yan JB, Wu WR, Dai JR, Li JS. 2007. Detection of quantitative trait loci and heterotic loci for plant height using an immortalized F2 population in maize. Chinese Science Bulletin 52, 477–483.

Tao DY, Xu P, Li J, Yang Y, Zhou J, Hu FY, Jones MP. 2003. Studies on hybrid sterility inheritance and mapping of sterile genes among near-isogenic lines derived from interspecific hybrid between cultivated rice species Oryza sativa L. and O. glaberrima Steud.. Chinese Journal of Rice Science 17, 11–15.

Virmani SS. 1994a. Heterosis and hybrid rice breeding. Springer-Verlag. International Rice Research Institute, P.O. Box 933, Manila, Philippines Theoretical and Applied Genetics 22, 192.

Virmani SS. 1999. Exploitation of heterosis for shifting the yield frontier in rice, Book of genetic and exploitation of heterosis in crops. International Rice Research Institute, P.O. Box 933, Manila , Philippines. Theoretical and Applied Genetics 22, 423–438.

Wan J, Ikehashi H. 1995. Identification of a new locus S-16 causing hybrid sterility in native rice varieties (Oryza sativa L.) from Tai-hu lake region and Yunnan Province, China. Breeding Science 45, 461–470.

Wan J, Ikehashi H, Sakai M, Horisue H, Imbe T. 1998. Mapping of hybrid sterility gene S17 of rice (Oryza sativa L.) by isozyme and RFLP markers. Rice Genetic Newsletter 15, 151–154.

Wan J, Yamaguchi Y, Kato H, Ikehashi H. 1996. Two new loci for hybrid sterility in cultivated rice (Oryza sativa L.). Theoretical and Applied Genetics 92, 183–190.

Wan J, Yanagihara S, Kato H, Ikehashi H. 1993. Multiple alleles at a new locus causing hybrid sterility between a Korean indica variety and a javanica variety in rice (Oryza sativa L.). Japanese Journal of Breeding 43, 507–516.

Wang C, Zhu C, Zhai H, Wan J. 2005.Mapping segregation distortion loci and quantitative trait loci for spikelet sterility in rice (Oryza sativa L.). Genetic Research 86, 97–106.

Wang GW, He Y Q, Xu CG Zhang QF. 2006. Fine mapping of f5-Du ,a gene conferring wide-compatibility for pollen fertility in inter-subspecific hybrids of rice (Oryza sativa L.). Theoretical and Applied Genetics 112, 382–387.

Wang J, Liu KD, Xu CG, Li XH, Zhang QF. 1998. The high level of wide-compatibility of variety Dular has a complex genetic basis. Theoretical and Applied Genetics 97, 407–412.

Wang S, Lu Z. 2006. Genetic diversity among parental lines of Indica hybrid rice (Oryza sativaL.). Plant Breeding 125, 606 – 612.

Wang Z, Yu C, Liu X, Liu S, Yin C, Liu L, Lei J, Jiang L, Yang C, Chen L, Zhai H, Wan J. 2012. Identification of Indica rice chromosome segments for the improvement of Japonica inbreds and hybrids. Theoretical and Applied Genetics 124, 1351–1364.

Wang ZQ, Jiang L, Yin CB, Wang XL, Lei JG, Xiao YL, Xi L, Liu SJ, Chen LM, Yu CY, Wan JM. 2013. QTL Mapping of Heterotic Loci of Yield-related Traits in Rice. Chinese Journal of Rice Science 27, 569– 576.

Warda. 2000. Report of the second Biennial Regional Consultative meeting of the National Experts Committee Meeting, M’bé, Bouaké, Côte d’Ivoire, 20–21.

Xin XY, Wang WX, Yang JS, Luo XJ. 2011. Genetic analysis of heterotic loci detected in a cross between indica and japonica rice (Oryza sativa L.). Breeding Science 61, 380–388.

Xu P, Zhou J, Li J, Hu FY, Deng XN, Feng SF, Ren GY, Zhang Z, Deng W, Tao DY. 2014. Mapping three new interspecific hybrid sterile loci between Oryza sativa and O. glaberrima. Breeding Science 63, 476–82.

Xu W, Virmani SS, Hernandez JE, Sebastian LS. 2002. Genetic diversity in parental line and heterosis of the tropical rice hybrids. Euphytica 127, 139 – 148.

Xue WY, Xing YZ, Weng XY, Zhao Y, Tang WJ, Wang L, Zhou HJ, Yu SB, Xu CG, Li XH Zhang QF. 2008. Natural variation in Ghd7 is an important regulator of heading date and yield potential in rice. Nature and Genetics 40, 761–767.

Yan CJ, Liang GH, Gu SL, Yi CD, Lu JF, Li X, Tang SZ, Gu MH. 2003. Molecular marker analysis and genetic basis for sterility of typical indica/japonica hybrids (in Chinese). Acta Genetica Sinica 30, 267–276.

Yanagihara S, Kato H, Ikehashi H. 1992. A new locus for multiple alleles causing hybrid sterility between an Aus variety and javanica varietiesin rice (Oryza sativa L.). Theoretical and Applied Genetics 90, 182–188.

Yang CY, Chen ZZ, Zhuang CX, Mei MT, Liu YG. 2004. Genetic and physical fine-mapping of the Sc locus conferring indica-japonica hybrid sterility in rice (Oryza sativa L.). Chinese Science Bulletin 49, 1718–1721.

Yang ZY, Liu WY. 1991. Classification of the F1 Intersubspecific Hybrids between Indica and Japonica and Its relation to the F1 Hybrid Vigor. Chinese Journal of Rice Science 5, 151–156.

Yokoo M. 1984. Female sterility in an indica-japonica cross of rice. Japanese Journal of Breeding 34, 219–227.

Zhang GQ, Lu YG, Zhang H. 1994. Genetic studies of the hybrid sterility in cultivated rice (Oryza sativa). IV. Genotypes for F1 pollen sterility (in Chinese). Acta Genetica Sinica 21, 34–41.

Zhang XQ, Wang XD, Jiang PD, Hua SJ, Zhang HP, Dutt Y. 2010. Relationship between molecular marker heterozigosity and hybrid performance in intra- and interspecific hybrids of cotton, Plant breeding 126, 385– 391.

Zhao JY, Li J, Xu P, Zhou J, Hu FY, Deng X, Deng W, Tao DY. 2012. A new gene controlling hybrid sterility between Oryza sativa and Oryza longistaminata. Euphytica 187, 339–344.

Zhao ZG, Jiang L, Zhang WW, Yu CY, Zhu SS, Xie K, Tian H, Liu LL, Ikehashi H, Wan JM. 2007. Fine mapping of S31, a gene responsible for hybrid embryo-sac abortion in rice (Oryza sativa L.).Planta 226, 1087–1096.

Zhao ZG, Wang CM, Jiang L, Zhu SS , Ikehashi H, Wan JM. 2006. Identification of a new hybrid sterility gene in rice (Oryza sativa L.). Euphytica 151, 331–337.

Zhou G, Chen Y, Yao W, Zhang CJ, Xie WB, Hua JP, Xing YZ, Xiao JH, Zhang QF. 2012. Genetic composition of yield heterosis in an elite rice hybrid. Proceedings of the National Academy of Sciences 109, 15847–15852.

Zhu SS, Jiang L, Wang CM, Zhai HQ, Li DT, Wan JM. 2005. The origin of weedy rice Ludao in China deduced by a genome wide analysis of its hybrid sterility genes. Breeding Science 55, 409–414.

Zhu SS, Wang CM, Zheng TQ, Zhao Z, Ikehashi H, Wan J. 2005. A new gene located on chromosome 2 causing hybrid sterility in a remote cross of rice. Plant Breeding 124, 440–445.

Zhu WY, Li WT, Ding XH, Zhang ZM, Zeng RZ, Zhu HT, Zhang GQ. 2008. Preliminary identification of F1 pollen sterility gene S-e in Oryza sativa (in Chinese with English abstract). Journal South China Agricultural University 29, 1–5.