ISSN:
1573-5060
Keywords:
Oryzasativa L.
;
rice
;
Xanthomonas campestris pv.
;
oryzae
;
bacterial leaf blight
;
resistance
;
induced mutations
;
seleetion
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Summary Dry seed lots of a rice cultivar, Harebare, susceptible for bacterial leaf blight (BLB), were exposed to thermal neutrons with and without pre-treatment of seed for boron-enrichment, and to gamma-rays. M1 plants of each of the treatments were grown and their seeds were separately harvested. M2 populations were raised in rice fields of a farmer in a region where BLB is epidemic every year, and M2 and control plants which expressed resistant reactions to BLB were selected. M3 and control lines as plant progenies of the selected M2 plants were raised in the same rice fields as in M2 generation in order to investigate their BLB resistance and other agronomically important traits. Variances for disease severity of M2 populations were significantly larger than those of the control population. whereas their means were not singificantly different from that of the control population, suggesting induction of mutations toward both resistance and susceptibility to BLB. Mean disease severity values of the M3 lines from selected M2 plants were significantly smaller than those of the control lines, indicating gains of selection in M2 for quantitative resistance against BLB. Thermal neutrons, especially with boron-enrichment pre-treatment were effective to induce mutations for resistance against BLB. Some M3 mutant lines with quantitatively enhanced resistance against BLB were not modified in other agronomic traits from those of the original cultivar. Significance of the induced quantitative resistance in breeding programmes for BLB resistance is discussed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00035392
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