Open AccessEpidemiological Effect of Gene Deployment Strategies on Bacterial Blight of Rice
Author(s) -
Hammad Ahmed,
Maria R. Finckh,
Rizal F. Alfonso,
Christopher C. Mundt
Publication year - 1997
Publication title -
phytopathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.264
H-Index - 131
eISSN - 1943-7684
pISSN - 0031-949X
DOI - 10.1094/phyto.1997.87.1.66
Subject(s) - biology , cultivar , bacterial blight , resistance (ecology) , sheath blight , gene , agronomy , xanthomonas oryzae pv. oryzae , veterinary medicine , botany , horticulture , genetics , rhizoctonia solani , medicine
Experiments were conducted in farmers' fields at two locations of the irrigated lowlands of Laguna province in southern Luzon island, Philippines, during the wet seasons of 1993 and 1994. Nine rice populations were studied including pure stands, two-component mixtures, two-gene combinations of backcrossed lines containing varying combinations of the bacterial blight resistance genes Xa-4, xa-5, and Xa-10, and a non-isogenic cultivar containing Xa-4 and partial resistance to bacterial blight. The area under the disease progress curve (AUDPC) of both gene combinations studied was significantly less than the single most effective gene of each combination deployed singly. A mixture of a susceptible and a resistant line expressed an AUDPC significantly less than the mean of its component pure stands, but two other mixtures did not. The cultivar IR20, which contains both Xa-4 and partial resistance, reduced the AUDPC by about two-thirds as compared with IR-BB4, which contains Xa-4 and little or no partial resistance.