Resistance and Tolerance of Commercial Onion Cultivars to Stem and Bulb Nematode, Ditylenchus dipsaci

摘要

Nematode resistance and tolerance reactions of 28 onion cultivars grown commercially in Turkey to stem and bulbnematode were studied at 20 °C, 70% RH and 16:8 h L:D photoperiod in growth chamber with 10 replications and at27±4 °C and 16:8 h L:D photoperiod in greenhouse with 3 replications, respectively. Ditylenchus dipsaci multiplied in allcultivars tested. The lowest multiplication was determined in cv. Valenciana from Atatürk Horticultural Central ResearchInstitute with 91 nematodes/pot and a multiplication rate of 0.5. Plant height of cultivars were significantly different inthe first tolerance experiment with having an average plant hight of 33.5 and 103.1 mm for inoculated and inoculatedplants, respectively (P0.05). Onion shoot diameter was statistically greater in nematode inoculated plants with 7.4 mmthan inoculated plants with 6.0 mm in second tolerance experiment (P0.05). Plant weight was not found different in bothtolerance experiments with nematode inoculation. There was not any statistically difference among cultivars for plantheight, plant diameter, plant weight and nematode multiplication in the experiments. Plant diameter for cv. Betapankoin first tolerance experiment and plant height for the Banko type onion in the second tolerance experiment sustainedsignificant negative correlations with nematode numbers. Plant weight for cv. Biotek Boran in second experiment, plantheight for cv. Taraz in second experiment and, plant diameter and plant weight for cv. Taraz in first tolerance experimentsustained significant positive correlations with nematode multiplication. It could be recommended that Valenciana couldlower nematode multiplication and Biotek Boran and Taraz could maintain a better plant development in nematodeinfested onion growing areas.