Development and Identification of Structural Variations Involving Chromosome 1J and 5J of Th. Bessarabicum L(?)ve
|School||Nanjing Agricultural College|
|Course||Crop Genetics and Breeding|
|Keywords||Thinopyrum bessarabicum Heterochromatin system DNA markers Radiation Physical location|
Thinopyrum bessarabicum (2n=2x=14, JJ or EbEb) confers multiple diseases resistance and salinity tolerance, which represents an important resource for wheat improvement. To transfer, locate and utilize these useful genes of this species, several Chinese Spring-Thinopyrum bessarabicum disomic- or multiple additions have been developed and characterized by Cytogenetics Institute, Nanjing Agricultural University, China. However, there is no line involving intact 1J were identified, which might influence the precisely mapping of both genes and molecular markers in Th.bessarabicum. In this paper, a new wheat- Th.bessarabicum disomic substitution line DS1J(1B) and 6 chromosome variations including two spontaneous translocations T1JS-W.W and TW.W-1JL were identified from the progenies of Chinese Spring and Chinese Spring- Th. bessarabicum by molecular, protein and cytogenetic markers. Using a set of Chinese Spring-Th. bessarabicum additions, 47 markers specific for 1J were identified. These markers were further mapped in chromosome variations involved 1J, and 5 were mapped on distal part of 1JL and 26 were on 1JS including two on distal,24 on middle and the others mapped on pericentric regions. 30 of 47 markers were in silico mapped in rice chromosome R2 and Brachypodium chromosome Bd3 indicating synteny of these chromosomes. Chromosome 5J of Th. bessarabicum confers salinity tolerance, in previous study, DA5J and DS5J (5A) have been developed. In this paper, in addition to two spontaneous translocations T5JS.5JL-W and TW.5JL identified, the other 50 kinds of structural variants involving chromosome 5J including reciprocal translocations, small segmental translocations and large segmental translocations were obtained from Ml seeds derived from Chinese Spring reciprocally crossed to DS5J(5A) after irradiated with 60Co-γ-rays (1200 rad dosage) at flowering date.32 markers specific for 5J were identified and 5 of them were mapped on 5JS,9 were mapped in the middle part and 15 were mapped on the distal part of 5JL.19 of 32 markers were in silico mapped in rice R2 and Brachypodium Bdl indiacting synteny of these chromosomes.