Title: Preliminary Evaluation of the Tolerance of 18 Pummelo Cultivars to Stem-Pitting Tristeza
Abstract:The tolerance of 18 pummelo cultivars to stem-pitting strains of Citrus tristeza virus (SP-CTV) was tested.Budlings of each cultivar maintained in a screen-house were graft-inoculated with severe tris...The tolerance of 18 pummelo cultivars to stem-pitting strains of Citrus tristeza virus (SP-CTV) was tested.Budlings of each cultivar maintained in a screen-house were graft-inoculated with severe tristeza isolates collected from diseased pummelo trees.The plants were heavily pruned each spring, and the degree of SP was rated on several occasions.Four cultivars (Meng-lunzao-you, Dian-jiang-bai-you, Man-sai-long-you and Chandler) showed high tolerance.Nine cultivars (Cui-xiang-tian-you, Tong-xian-you, Nan-kang-zao-you, Tai-bei-you, Feng-huang-you, Bai-shi-you, Wu-bu-you, Yu-huan-you and Guan-xi-mi-you) were susceptible, and most of these plants showed severe SP.The other five cultivars (Wan-bai-you, Long-an-you, Ling-nan-sha-tian-you, Chang-shousha-tian-you, and Liang-shan-you) were moderately susceptible.After preliminary tests showed that Chandler was tolerant to SP-CTV, it was grafted to 32 pummelo budlings or young trees with pummelo dwarf symptoms.After 2-3 yr, Chandler scions showed no stem-pitting or only a few pits.Budlings of Chandler, graft-inoculated with severe isolates collected from diseased pummelo trees from four different counties, also remained free of stem-pitting 3 yr post-inoculation.Read More