Sexuality and compatibility of Bipolaris sorokiniana and segregation pattern in teleomorph (Cochliobolus sativus): geographic origin and segregation ratio

• Published in: Indian phytopathology 2018-09, Vol.71 (3), p.365-375
• Main Authors: Sultana, S., Adhikary, S. K., Rahman, S. M. Mahbubur, Islam, M. M.
• Format: Article
• Language: English
• Subjects: Biomedical and Life Sciences; Life Sciences; Plant Pathology; Research Article
• ISSN: 0367-973X; 2248-9800
• DOI: 10.1007/s42360-018-0066-3

Bipolaris sorokiniana causes leaf blotch of wheat, inflicting substantial grain yield losses in worldwide. Knowledge of sexual recombination of the fungal pathogen can help to implement effective disease management strategies. Randomly selected 51 isolates of B. sorokiniana was studied to test compatibility with all possible combinations. Six most fertile crosses were found, among them two combinations (BS-81 x BS-83 and BS-60 x BS-134) produced abundant pseudothecia with mature and viable ascospores. This result disclosed that most compatible isolates belonging in the Lower and High Ganges river floodplain area of Bangladesh. One hundred and fifty ascospores were examined to evaluate morphological segregation pattern. Morphological characters (ascospores color, shape, size, Septation number and colony color) of ascospores reject the null hypothesis. A clear 3:1 and 9:7 segregation ratios for ascospores color, mycelial colony color, shape of ascospores; and size of ascospores, septation number of ascospores were found in F2 progeny. RAPD technique was tested to determine molecular segregation pattern in 75 F2 progeny following reproducible polymorphic prominent bands. After test of independence, each trait showed significant and fit to the 1:1 segregation ratio expected for Mendelian trait.