|Perez, Paola T -|
|Cianzio, Silvia R -|
|Kara, P -|
|Aviles, Mayra -|
Submitted to: Journal of Crop Improvement
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 13, 2010
Publication Date: April 4, 2011
Citation: Perez, P., Cianzio, S., Kara, P.C., Aviles, M., Palmer, R.G. 2011. QTL mapping of whitefly resistance in soybean. Journal of Crop Improvement. 25:134-150. Interpretive Summary: Abiotic and biotic stresses of plants result in a decline in quality and quantity. One of the most devastating pests world-wide is the whitefly. Damage can be caused by direct feeding on plants, but also by virus transmission while feeding. Whiteflies have been reported on soybean in the United States and in certain areas in Mexico. Soybean plantings have been banned due to heavy whitefly infestations that could also spread to other plants. Our objective was to determine the inheritance of resistance to whitefly and to locate the resistance gene(s). Two populations of the same susceptible soybean were crossed with two different resistant soybeans. The genetic materials were evaluated for two years at one location in Northwest Mexico where whitefly is a major recurring pest of soybean. Resistance factors were at several locations of the soybean genome and resistance was considered a polygenic trait. The identification and location of these resistant genes will help the plant breeder accumulate many resistance genes to be bred into cultivars. These cultivars resistant to whitefly infestation should be higher in yield, which translates into more profitable soybean production for the farmer.
Technical Abstract: Whitefly Bemisia tabaci (Gennadius) is one of the most damaging insects attacking crops in the world. In soybean [Glycine max (L.) Merr.], in addition to causing plant stress and reduced seed size, they also can be vectors of viruses, e.g. soybean crinkle mosaic, and soybean dwarf mosaic. Resistance to whitefly in soybean has been reported; however, whitefly resistance genes have not been identified. The objective of the study was to identify quantitative trait loci (QTL) for whitefly resistance in soybean. Two F2 segregating populations, derived from crosses between whitefly resistant lines ‘Cajeme’ and 'Corsoy 79' and the susceptible line ‘Williams 79’, were developed to determine inheritance of resistance to B. tabaci. Parental lines were screened with simple sequence repeats (SSR). Segregating F2 populations and parents were evaluated for whitefly infestation for two years at one location in Northwest Mexico, where whitefly is a recurrent pest of soybean. QTL analyses were performed using standard interval mapping (SIM), and composite interval mapping (CIM). Results indicate that whitefly resistance is a polygenic trait, controlled by QTL on different chromosomes. The significant QTL detected in this study were located on chromosomes 12, 18, and 19 (formerly molecular linkage groups H, G, and L, respectively). In addition, there are was evidence that other QTL could be involved in resistance, such as those detected on chromosomes 1, 7, 17, 10, and 16 (formerly molecular linkage groups D1a, M, O, J, and D2, respectively). Fine-mapping of the large effect QTL detected in this study would be helpful to identify tightly linked markers for use in marker-assisted selection (MAS) for whitefly resistance in soybean.