Breeding of the Scab-Resistant Pear Cultivar ‘Greensis’

To develop scab-resistant pear (Pyrus spp.) varieties with fruits that are as crisp and juicy as Asian pears, a cross was made between ‘Whangkeumbae’ and ‘Bartlett’ varieties (P. pyrifolia × P. communis) at the Pear Research Institute of the National Institute of Horticultural & Herbal Science, Rural Development Administration, in 1994. Among the 285 seedlings, ‘Greensis’ was first selected in 2006 for its good eating quality and named in 2012 after regional adaptation tests in nine regions and ten experimental plots from 2007 to 2012. The tree showed a vigorous growth habit and semi-spreading characteristics, like ‘Whangkeumbae’. The optimum fruit harvest date was also around Sept. 26 and fruit was round in shape and green in skin color at maturity. Average fruit weight was 470g, and the soluble solids content was 12.4°Brix. The flesh was very crisp and juicy, and had good eating quality. Its’ leaf size was similar with ‘Bartlett’ and smaller than ‘Whangkeumbae’. The average of full bloom date of ‘Greensis’ was determined as Apr. 26, which was six days later than ‘Whangkeumbae’ and similar with ‘Bartlett’. S genotypes of ‘Greensis’ were identified as S4Se by S-allele PCR product sequencing analysis. It seems that the S4 allele was inherited from ‘Whangkeumbae’ and the Se allele from ‘Bartlett’. ‘Greensis’ displayed strong resistance to scab disease caused by Venturia nashicola , similar to European pear cultivars like ‘Beurre Hardy’ and, ‘Conference’. ‘Greensis’ was also highly resistant to black leaf spot (Alternaria kikuchiana) in the field