|G. Lācis, I. Kota-Dombrovska, B. Lāce
|pear, germplasm, molecular markers, characterization, breeding
A limited assortment of pear cultivars is dominating in global production which should be diversified considering the potential climate change, challenges of disease expansion and demand for safe and healthy products.
Pear scab caused by Venturia pyrina is one of the most important diseases which growers have to deal with.
Current methods of pear scab control are based mainly on pesticide applications.
To increase scab resistance, broader Pyrus germplasm should be involved in growing and especially in breeding.
Therefore, this study aimed to assess the genetic diversity of Pyrus germplasm available in the Latvian genetic resources collection, as well as to test the applicability of molecular markers associated with scab resistance.
Forty pear genotypes of different origin were included in the study, like cultivars and hybrids bred in Latvia, landraces collected during expeditions throughout the country, as well as introduced foreign cultivars.
Twenty-three microsatellite (SSR) markers were selected for testing, based on the following criteria: proven association with scab resistance genes or mapped scab resistance QTLs.
Since information on pear resistance to scab is relatively limited, molecular markers developed in apple and linked to apple scab resistance were involved considering high genome synteny between Malus and Pyrus. Successful amplification in all genotypes was found for 22 SSR markers.
On average 8.7 putative alleles per primer were identified, ranging from 4 to 17, providing each genotype with a unique fingerprint.
Marker data analyses did not show strict division of genotypes into groups, but showed genetic dispersion.
Additionally, the genotyping information was supplemented with available data on pear scab severity, observed in the field, to clarify possible associations and evaluate marker suitability in pear scab resistance evaluation.
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