Development and mapping of AFLP markers linked to the sorghum fertility restorer gene rf4

Abstract

The restoration of male fertility in the sorghum IS1112 C (A3) male-sterile cytoplasm is through a two-gene gametophytic system involving complementary action of the restoring alleles Rf3 and Rf4. To develop markers suitable for mapping rf4, AFLP technology was applied to bulks of sterile and fertile individuals from a segregating BC(3)F(1) population. Three AFLP markers linked to rf4were identified and subsequently converted to STS/CAPS markers, two of which are co-dominant. Based on a population of 378 BC(1)F(1) individuals, two STS/CAPS markers, LW7 and LW8, mapped to within 5.31 and 3.18 cM, respectively, of rf4, while an STS marker, LW9, was positioned 0.79 cM on the flanking side of rf4. Markers LW8 and LW9 were used to screen sorghum BAC libraries to identify the genomic region encoding rf4. A series of BAC clones shown to represent a genomic region of linkage group E were identified by the rf4-linked markers. A contig of BAC clones flanking the LW9 marker represent seed clones on linkage group E, from which fine mapping of the rf4 locus and chromosome walking can be initiated.

Application of LW7 marker for identification of progenies with male sterility gene in sweet sorghum population

“…PCR was carried out in 20 μl reaction mixture containing 50 ng of DNA template, 1X PCR buffer, 0.2 mM dNTPs, 1.8 mM MgCl 2 , 1 Unit Taq polymerase, 0.25 μl E-CTA/5'-GATCTACATATGTGGAGCTC-3' and M-CAC/5'AGAT CTCGGCGCTGCGGAGCAGAA-3' of LW7 marker (Wen et al 2002), and 6.96 μl of dH 2 O.…”

“…Bands were then scored (1) for presence or (0) for absence of banding at 779 bp (Wen et al 2002). The data of PCR reactions were recorded as 1 or 0 for the presence of 779 bp or absence of the bands, respectively.…”

“…DNA-based molecular markers tightly linked to fertility restorer genes have also been identified in several other species such as rice (Akagi et al 1996, Ichikawa et al 1997, Zhang et al 1997, petunia (Bentolila et al 1998, Bentolila andHanson 2001), barley (Matsu et al 2001), sunflower (Horn et al 2003, cotton (Gossypium hirsutum; Liu et al 2003), wheat (Zhou et al 2005), chili pepper (Kim et al 2006) and sorghum (Klein et al 2001, Jordan et al 2010, Jordan et al 2011. In sweet sorghum, DNA markers associated with several morphological traits (Shehzad et al 2009), agronomic traits (Yun-long et al 2006, Ritter et al 2008) and stem sugar-related traits (Ritter et al 2008, Shiringani et al 2010) have been identified and mapped into sorghum genetic linkage map (Ritter et al 2007, Srinivas et al 2009 (Klein et al 2001); SSR Xtxp304 (Jordan et al 2010); LW7; LW8; and LW9 marker (Wen et al 2002). These markers provide a powerful tool for practical breeding of sweet sorghum hybrids.…”

“…Nevertheless, LW7 was polymorphic and was selected for use in marker assisted selection program (Lunmat et al 2008). LW7 was extensively used in grain sorghum (Wen et al 2002). However, the application in sweet sorghum to develop B-lines has not been reported.…”

DNA markers reveal genetic structure and localized diversity of Ethiopian sorghum landraces

“…Polymerase chain reaction (PCR) based assays for plant DNA fingerprinting such as AFLP (Vos et al, 1995), SSR (Tautz and Renz, 1984) and ISSR (Zietkiewicz et al, 1994) have become widely used. These markers have been widely used for reliable and robust characterization of crop genetic resources (Godwin et al, 1997;Pejic et al, 1998;Smith et al, 2000;Wen et al, 2002;Uptmoor et al, 2003;Medraoui et al, 2007;Weerasooriya et al, 2016). With the development of high-throughput sequencing (or next-generation sequencing-NGS) technologies in recent years, marker techniques such as single nucleotide polymorphism (SNPs) and genotyping by sequencing (GBS) have become very useful for exploring the diversity within plant species, constructing haplotype maps and performing genome-wide association studies as well as genomicsassisted breeding (He et al, 2014).…”