Open AccessScreening for Powdery Mildew Resistance in Pulmonaria
Author(s) -
Kimberly H. Krahl
Publication year - 2004
Publication title -
hortscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.518
H-Index - 90
eISSN - 2327-9834
pISSN - 0018-5345
DOI - 10.21273/hortsci.39.1.161
Subject(s) - powdery mildew , biology , cultivar , inoculation , horticulture , mycelium , plant disease resistance , botany , resistance (ecology) , agronomy , biochemistry , gene
A screening technique was developed for studying resistance to powdery mildew disease in 25 diverse Pulmonaria L. species and cultivars. Healthy Pulmonaria plants were inoculated by drawing naturally infected leaves of P. angustifolia `Blaues Meer' across the abaxial surface of three healthy, mature leaves per test plant. Inoculated leaves were rated for powdery mildew infection using a scale of 0-5, where 0 = no visible sign of infection, 1 = 1% to 20%; 2 = 20% to 40%; 3 = 40% to 60%; 4 = 60% to 80%; 5 = 80% to 100% of leaf surface covered with white mycelial growth. Each genotype was inoculated and evaluated four times. The data revealed a wide and continuous range of variability for powdery mildew disease incidence in the 25 lungwort genotypes that may be indicative of quantitative resistance. The majority of lungwort genotypes exhibited low levels of resistance to powdery mildew. Four cultivars ( P. hybrid `Spilled Milk', P. hybrid `Excaliber', P. rubra `Redstart', and P. rubra `David Ward') and one selection ( P. longifolia ssp. cevennensis ) exhibited high levels of resistance to powdery mildew. Since Pulmonaria species intercross readily, these genotypes may be useful in the future development of new powdery mildew resistant Pulmonaria cultivars.