Title:	Development and breeding of herbicide tolerant lettuce.
Authors:	NAGATA, R. T. DUSKY, J. A. TORRES, A. C. CANTLIFEE, D. J.
Affiliation:	ANTONIO CARLOS TORRES, CNPH.
Date Issued:	1992
Citation:	Proceedings Florida State Horticulture Society, v. 105, p. 358-361, 1992.
Description:	Weed control measures for lettuce, Lactuca sativa L. on south Florida high organic soils (>70%) can exceed $600 per acre due to the high use of manual labor. Available chemical herbicides are ineffective for broad spectrum control of weeds. It is the aproach of the lettuce breeding program of weeds. It is the aproach of the lettuce breeding program of the University of Florida to develop herbicide tolerant lettuce cultivanrs through classical and gene splicing methodology. Sulfonylurea herbicide resistance was derived from prickly lettuce, L serriola L and backcrossed into crisphead, cos, bibb and leaf lettuce thet have desirable disease resistance and commercial quality. Inheritance of the herbicide resistance was through an incomplete dominance gene action. Good expression of resistance in lettuce was observed at 2 oz/acre rate of imazethapyr. Segregation ratios for backcrossing was 1:1, tolerantrsusceptible. F2 segregation for resistance:tolerant:susceptible was in a 1:2:1 ratio. Breeding lines of leaf, cos, crisphead and butterheads resistant and tolerant to sul fonylurea herbicides have been developed. Closed heading types are progressing slower than open head types due to multiple genes involved in heading. Glyphosate resistance was bioengineered into 'South Bay7 lettuce through the use of Agrobacterium tumefaciens as the vector. A total of 73 individual family lines, each representing a independent transformation event have been generated. Seed were collected for each line. Initial screening of regenerated 'South Bay' crisp head lettuce with the incorporated gene have indicated good resistance to glyphosate at a use rate of 2 Ib/acre. The mechanism of gene action is believed to be dominant. Homo-zygous lines have been identified and studies are continuing.
Thesagro:	Alface Biotecnologia Erva Daninha Herbicida Lactuca Sativa Melhoramento
NAL Thesaurus:	breeding glyphosate herbicides lettuce weeds
Keywords:	Tolerancia Glisofato Planta daninha Agrobacterium tumaefaciens Tolerance
Type of Material:	Artigo de periódico
Access:	openAccess
Appears in Collections:	Artigo em periódico indexado (CNPH)