|MOORE, P - Washington State University|
Submitted to: International Rubus Ribes Symposium
Publication Type: Abstract Only
Publication Acceptance Date: 1/30/2011
Publication Date: N/A
Technical Abstract: The root lesion nematode, Pratylenchus penetrans, is a production-limiting pest in red raspberry, Rubus ideaus, in the United States. Having resistance as a tool to manage P. penetrans in raspberries would reduce the impact of this nematode on raspberry productivity as well as reduce the need for pre- and/or post-plant chemical treatments to keep this nematode in check. Eleven Rubus spp. (R. coreanus, R. crataegifolius, R. innominatus, R. leucodermis, R. niveus, R. parviflorus, R. parvifolius, R. pungens, R. spectabilis, R. sumatranus, and R. odoratus) three F1 hybrids (Meeker x R. cockburnianus, Tulameen x R. lasiostylus, and Tulameen x R. phoenicolasius) and the Rubus idaeus cultivar Meeker were evaluated in greenhouse trials for P. penetrans resistance. One-month-old plants in 3.8 liter pots were inoculated with 1,800 P. penetrans; noninoculated controls were included. Plants were allowed to grow for an additional three months at which time plants were destructively harvested and P. penetrans/g root, P. penetrans/50 g soil, total P. penetrans/pot, and root and above-ground biomass were determined. Rubus innominatus was the best host for P. penetrans with a reproduction factor (Rf = final population/initial population) of 3.6, but this was not significantly different from the species with the next highest Rf, R. parviflorus with Rf of 1.66. Meeker had an Rf value of 0.88. There was no difference in the P. penetrans host status of most of the Rubus materials tested, with Rf values ranging from 0.1 to 0.96. However, based upon the number P. penetrans/g root, R. niveus hosted fewer nematodes compared to the rest of the tested Rubus materials except for R. leucodermis, R. sumatranus and R. odoratus. When P. penetrans inoculated plants were compared to noninoculated plants within a Rubus spp., there were few consistent trends of nematode parasitism on root or above-ground growth. In fact, R. innominatus, which supported the highest P. penetrans population densities, had greater shoot biomass in plants inoculated with P. penetrans compared to the noninoculated plants.