The dioecious genus is thought to include two wild relatives (Ilj.

The dioecious genus is thought to include two wild relatives (Ilj. is the heterogametic sex (XY) in Group 2, mainly because is the case in L. (Group 1). Cytogenetic and DNA marker analyses suggested that Group 1 and Group 2 have homomorphic and heteromorphic sex chromosome pairs (XY), respectively, and that the sex chromosome pairs of the two groups developed from a common ancestral pair. Our data suggest that the genus may serve as a good model for investigation of evolutionary mechanisms underlying the emergence of heteromorphic sex chromosome pairs from ancestral homomorphic pairs. L.), sorrel (L.), and hemp (L.), etc.; however, homomorphic sex chromosome pairs also are found in many dioecious vegetation, for example, spinach (L.), asparagus (L.), and buy 885325-71-3 papaya (L.). Sex chromosome pairs are derived from autosomal pairs, strongly suggesting the evolutionary transition from homomorphic to heteromorphic sex chromosome pairs. Therefore, homomorphic and heteromorphic sex chromosomes that have emerged in various angiosperm lineages may represent different evolutionary phases, providing a great opportunity to examine early sex chromosome development (Ming 2011; Charlesworth 2013). Spinach (L.) is definitely a member of (a subfamily of the alliance) (Kadereit 2003), and probably one of the most nutritious leafy vegetables cultivated worldwide (FAOSTAT, http://faostat3.fao.org/home/index.html). It is generally regarded as a dioecious varieties with wind pollination, although particular cultivars, lines, and crosses can create individual vegetation with both male and female Rabbit polyclonal to MBD3 flowers (2008). Earlier genetic studies, including examinations of various synthetic polyploids, buy 885325-71-3 show that spinach possesses a male-heterogametic (XX/XY) sex dedication system with an active Y chromosome. Trisomy analysis offers located a sex-determining locus on the largest chromosome of the match (Janick and Stevenson 1954, 1955b; Ellis and Janick 1960; Sugiyama and Suto 1964). In cytogenetic analyses of a wide range of spinach varieties and germplasm accessions, no obvious heteromorphism of the largest chromosome (sex chromosome, XY) pair has been observed, with rare exceptions (Lorz 1937; Bose and Janick 1961). The largest chromosome has a submedian centromere in most spinach stocks; however, a longer and median (metacentric/homobrachial) variant of the chromosome, which is likely due to a translocation event, was found in a spinach accession (PI 169671) from Turkey (Iizuka and Janick 1962). The longer variant along with the standard chromosome could form a heteromorphic pair. A recent study using fluorescence hybridization (FISH) reported that spinach sex chromosomes might be differentiated by the loss buy 885325-71-3 of a 45S rDNA locus from 2006). However, intraspecific copy quantity variance of ribosomal RNA genes, as well as intraspecific numerical variance of rDNA loci, has been observed in a wide range of flower varieties (Rogers and Bendich 1987; Kataoka 2012), so further verification is required to determine whether variance in the 45S rDNA locus in spinach is definitely associated with sexual dimorphism. The genus is known to contain two crazy relatives (Ilj. and Stev.) of cultivated spinach (L.) (Sneep 1982; Hammer 2001). (Note that Roxb. is now regarded as synonymous with L. [Lorz 1937; Sneep 1982].) Currently, germplasm accessions of crazy spinach relatives are stored in gene banks in the United States and Europe and are regarded as important resources for future spinach breeding. However, little is known about genetic relationships among buy 885325-71-3 varieties. Ilj. has been described as the closest relative of L. (Hammer 2001), and relating to Hooker and buy 885325-71-3 Jackson (1895) and Volkens (1893), Stev. is definitely unique from L. (Lorz 1937). However, recent molecular phylogenetic analyses failed to display that Stev. is definitely a distinct varieties (Hu 2007). Lorz (1937) also failed to display any significant karyotypic difference between Stev. and L., and did not observe heteromorphism in.

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