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ARS Home » Northeast Area » Kearneysville, West Virginia » Appalachian Fruit Research Laboratory » Innovative Fruit Production, Improvement, and Protection » Research » Publications at this Location » Publication #298352

Title: Fruit quality of pear psylla-resistant parental germplasm

Author
item BELL, RICHARD

Submitted to: HortScience
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/11/2013
Publication Date: 2/26/2014
Citation: Bell, R.L. 2014. Fruit quality of pear psylla-resistant parental germplasm. HortScience. 49(2):138-140.

Interpretive Summary: Pear psylla are the most important insect pests of pears in North America and Europe, causing a degradation in fruit size, quality and production, as well in tree health. Breeding for resistance to this pest is a major objective of most pear breeding programs in these regions. Selection of parents for the development of new resistant varieties involves evaluation of both the degree of susceptibility or resistance, but also importantly, the fruit quality of potential parents. Fifteen selections and one variety developed by breeding programs, which had been previously determined to be resistant to pear psylla, were evaluated for nine fruit quality traits and a multi-trait index score. The purpose of the study was to determine which pear selections have the best fruit quality and should be incorporated into our breeding program. Using the best quality parents will enhance the rate of development of new psylla-resistant pear varieties to alleviate one of the most important and expensive production problems of the U.S. pear industry.

Technical Abstract: Sixteen interspecific backcross hybrid selections from various breeding programs have been selected as prospective parents for breeding for resistance of European-type pears to the pear psyllids (Cacopsylla spp.). The Pyrus communis x P. pyrifolia (n equal 6) backcross selections are derived mostly from NJ 1, an open-pollinated P. pyrifolia seedling, and the Pyrus communis x P. ussuriensis (n equal 9) backcross selections are derived from Illinois 76, an open-pollinated P. ussuriensis seedling, and one Pyrus communis x P. ussuriensis cultivar. Ratings of psylla resistance have been based primarily upon multi-year orchard observations under no-pesticide and minimal pesticide conditions. In order to select the best prospective parents, data on fruit quality and tree traits were analyzed. Fruit characteristics included harvest date, fruit size and shape, skin color, percentage blush, russet, overall appearance, texture (flesh fineness), texture type, juiciness, overall grittiness and grit size, flavor acceptability and type, aroma, and a quality index which was an unweighted total of the scores for appearance, texture, grit, flavor, and aroma. For this report, comparisons were made to ‘Bartlett’, the most widely grown US pear cultivar. Both the P. communis x P. pyrifolia and Pyrus communis x P. ussuriensis backcross hybrid groups had significantly lower quality indices that ‘Bartlett’, and most individual traits were similar in this respect. There were significant differences among selections for all traits, as were differences between years within genotype for most traits with some exceptions. Harvest date, percentage blush, appearance, juiciness, flavor, and the quality index were relatively stable from year to year. Flesh texture type varied within each group. The P. communis x P. pyrifolia selection NJ Rock R23 T252 had the highest quality index of the selections. For eight traits, various selections ranked higher than ‘Bartlett’, although the differences were not significantly higher, with the exception of the russet score. Five selections appear to have sufficient quality and are being used as parents.