The Choromosomal Assesment of Salt Tolerant Substituted Tritipyrum Using Genomic Fluorescentin situ Hybridization (FISH)

Document Type: Research Paper

Authors

1 Department of Agronomy and Plant Breeding, College of Agriculture, Shahid Bahonar University of Kerman, Kerman, Iran.

2 School of plant sceince, Department of agricultural botany, The university of Reading, Whitgeknights, Reading, RG6 6AS.UK.

3 John Innes center, Norwich Research Park, colney, Norwich, NR4 7UH, U.K.

Abstract

Wheat, although moderately tolerant to salt, can not be cultivated in many areas. However, in the triticeae
tribe, some of the wild wheat relatives are highly tolerant, e.g. Thinopyrum bessarabicum, which grows on
the sea shore. Eight primary hexaploid tritipyrum lines, amphiploids between Triticum durum and Thinopyrum
bessarabicum have been produced which can set seed in at least 250 mM NaCl. These tritipyrums (2n=6x=42, AABBEbEb) due to reasons such as brittle rachis, continuous production of tillers, late maturity, tall stature and meiotic instability will not fulfill the requirements of a successful commercial salt tolerant crop. To overcome such problems the substituted tritipyrum, in which selected Eb chromosomes are replaced by D genome chromosomes of 6x wheat, was produced from 6x tritipyrum x 6x wheat hybrids (F1:2n=6x=42, AABBDEb) followed by selfing and backcrossing with 6x tritipyrum. The fertile plants among the above progenies were screened by the genomic fluorescent in situ hybridization technique to identify their Eb and D chromosome constitution. This study showed that producing tritiprum with variable numbers of Eb and D genome  chromosomes is feasible and that FISH is a useful technique for determining the number of Eb chromosomes present.

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