Production of haploid wheat plants from wheat (<i>Triticum aestivum</i> L.) x maize (<i>Zea mays</i> L.) cross system

Abstract

The present study was carried out taking single F1 wheat and four maize varieties, viz. Arun-1, Arun-2, Khumal Yellow and Rampur Composite, to determine the efficiency and influence of maize genotypes on various parameters of haploid formation. Wheat spikelets were hand pollinated with freshly collected maize pollen, and 1 ml of 100 ppm 2,4-D was immediately injected on the uppermost internode. Twenty-four hours after 2,4- D injection, the cups of the florets were filled with the same solution of 2,4-D for two more consecutive days. Seventeen days after pollination, the embryos were excised and cultured in half-strength MS basal medium supplemented with 30 g/l sucrose, and 7 g/l agar. The cultured embryos were maintained at 25°C with 16/8 hours light/darkness after treating in the dark for seven days at 4°C and incubation in the dark for seven days at 25°C. Application of 2,4-D after pollination was found to be essential to the recovery of culturable size of embryos. The significant effect of maize genotypes on frequency of ovary development, embryo formation and haploid plant per pollinated floret was observed. The mean percentages of embryo formation and haploid plants per pollinated floret varied from 5.17 to 21.45 and 0.96 to 10.15, respectively, depending upon the maize varieties used. The highest frequency of embryo recovery and plant per floret was found when wheat F1 was pollinated with Arun-2 followed by Arun-1 and Khumal Yellow. It is suggested that the production of dihaploids (DHs) in wheat can be enhanced by using more responsive maize genotypes as pollinators. &#x0D; &#x0D; Key words: 2,4-D, caryopsis, floret, haploid embryo, wheat x maize cross &#x0D; &#x0D; Himalayan Journal of Sciences Vol.4(6) 2007 p.65-69

Recent advances and application of doubled haploids in wheat breeding

“…Production of haploids in wheat through wheat x maize crossing was reportedsuccessful without the development of albino plants (Sadasivaiah et al, 1999;Ushiyama et al, 2007) and insensitivity of maize to the action of crossability inhibitor (Kr) genes. Several reports demonstrated the success of doubled haploid plant production using maize pollen on hexaploid wheat (Suenga and Nakajima, 1989;Amrani et al, 1993;Niroula et al, 2007) maize (Almouslem et al, 1998;David et al, 1999;Garcia-Llamas et al, 2004). Recently, Sourour et al (2012) have reported the production of successful DH durum wheat genotypes using the wheat x maize system.…”

“…But this technique is quite advantageous where synchronization is a problem. Once the pollination is complete, the application of auxin is essential for the successful recovery of haploid wheat embryos (Suenga and Nakajima, 1989;Niroula et al, 2007). Recently, frequency of polyhaploid embryo formation has greatly improved through the manipulation of Dicamba alone or in combination with 2,4-dichlorophenoxyacetic acid (2,4-D) (Almouslem et al, 1998;O'Donoughue and Bennett, 1994;Garcia-Llamas et al, 2004;Ahmad and Chowdhry, 2005).…”

“…Recently, frequency of polyhaploid embryo formation has greatly improved through the manipulation of Dicamba alone or in combination with 2,4-dichlorophenoxyacetic acid (2,4-D) (Almouslem et al, 1998;O'Donoughue and Bennett, 1994;Garcia-Llamas et al, 2004;Ahmad and Chowdhry, 2005). Embryo rescue is essential to recover haploid plantlets from wheat x maize system (Sood et al, 2003;Suenga and Nakajima, 1989;Niroula et al, 2007;Zhang et al, 1996;Niroula and Bimb, 2009) after 14 to 20 days of post pollination. Excised embryos can be cultured on either full strength MS (Murshige and Skoog, 1962) or ½ MS or B5 basal medium (Gamborg et al, 1968) containing various modifications of organic supplements (Zenkler and Nitzsche, 1984;Zhang et al, 1996;Suenga et al, 1997;Campbell et al, 2000;Singh et al, 2004;Ayed et al, 2011) and can be grown in vitro for 3 to 5 weeks at 20 to 25°C and 16 h day length.…”

An insight into wheat haploid production using wheat x maize wide hybridization

“…The excised haploid embryos were cultured on half strength MS based media without phyto-hormones with 30 gm/l sucrose and 0.7% agar [10,20] (Figure 1). The cultured plates were kept at 25±2 °C temperature and 16 hrs photoperiod until the development of 3-5 cm plantlet.…”

“…Several haploid production systems have been reported in wheat including anther culture [1,2,3], microspore culture [4,5,6,7] and intergeneric crosses with maize [8,9,10], sorghum [11], Hordeum bulbosum L. [12] and pearl millet [13]. The haploid wheat embryo production was reported for the first time by crossing between wheat and maize [14].…”