Selection of Mungbean Resistant to Powdery Mildew In BC1F1 Progenies based on ISSR and ISSR-RGA Markers
Utilization of molecular markers linked to a trait of interest for selection ofdesirable progenies (marker assisted selection; MAS) is useful for plant breeding. It can be carried out at all stages of plant growth and in all environments. In this study, we used inter-simple sequence repeat (ISSR) and ISSR-anchored resistance gene analog (ISSR-RGA) markers associated with powdery mildew (PM) resistance to select PM resistantmungbean BC1F1 progenies and confirmed their resistance through detached leaf assay. BC1F1 progenies were derived from crosses between CN72 and F1 (from sixteen crosses), which derived from double crosses of recombinant inbred lines (RILs) from three populations (A [CN72 × V4758], B [CN72 × V4718] and C [CN72 × V4785]). A total of 99BC1F1 progenies were screened using 3 markers consisting of I85420, I42PL222 and I42PL229.Two of these markers are linked with a PM resistance allele (I85420 and I42PL222) while the marker I42PL229 is linked with a susceptible allele. All BC1F1 progenies were found to have a band that associated with I42PL229 marker while 53 and 67 BC1F1 progenies were detected with bands associated with I85420 and I42PL222 markers, respectively. Among these, 36 were found to carry both bands linked to PM resistance from the resistant parent. Subsequently, whena total of 53 BC1F1 progenies with a I85420 marker band were verified for PM resistance using detached leaf assay, 50 BC1F1 progenies were identified to be PM resistant(94.3%accuracy).Meanwhile, when using both I85420 and I42PL222 markers for screening, 34 out of the 36 BC1F1 progenies were verified to be PM resistant, suggesting 94.4%accuracy.These results indicate that both markers are efficient tools for the selection of PM resistant mungbean progenies and using only I85420 marker is sufficient for rapid screening of PM resistance in the next generations.
Keywords - Mungbean, BC1F1 progenies, powdery mildew (PM), inter-simple sequence repeat (ISSR), ISSR-anchored resistance gene analog (ISSR-RGA)