PRODUCTION OF A NOVEL ROBERTSONIAN TRANSLOCATION FROM THINOPYRUM BESSARABICUM INTO BREAD WHEAT.

Area of Science:

• Plant genetics and breeding
• Cytogenetics
• Crop improvement

Background:

• Wheat improvement relies on developing novel genetic resources.
• Alien translocations offer a pathway to introduce desirable traits into wheat.
• Robertsonian translocations (RobTs) are a specific type of chromosomal rearrangement.

Purpose of the Study:

• To produce compensating wheat-Th. bessarabicum whole arm Robertsonian translocations (RobTs).
• To involve wheat chromosome 2B and Th. bessarabicum chromosome 2E(b) using centric breakage-fusion.
• To identify and select stable translocation lines for wheat breeding.

Main Methods:

• Crossing a DS2E(b)(2B) substitution line with bread wheat 'Roushan'.
• Screening F2 populations using 2E(b) specific PCR-based Landmark Unique Gene (PLUG) markers.
• Cytogenetic analysis of F2 and F3 generations to confirm translocations.

Main Results:

• Two RobTs were identified among the F2 plants.
• Homozygous translocation lines (T2E(b)S.2BL) were selected from F3 families.
• The selected T2E(b)S.2BL stock exhibited good vigor, full fertility, and longer awns than parents.

Conclusions:

• Compensating wheat-Th. bessarabicum RobTs involving chromosomes 2B and 2E(b) were successfully produced.
• The cytogenetically stable T2E(b)S.2BL stock is a valuable resource for wheat improvement.
• This translocation may enhance desirable traits such as awn length in wheat cultivars.