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Recurrent Selection for Tolerance to Phytophthora Rot in Soybean 1
Author(s) -
Walker A. K.,
Schmitthenner A. F.
Publication year - 1984
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci1984.0011183x002400030016x
Subject(s) - biology , phytophthora , phytophthora megasperma , cultivar , population , horticulture , selection (genetic algorithm) , greenhouse , agronomy , phycomycetes , inoculation , demography , artificial intelligence , sociology , computer science
Evidence suggests that tolerance to phytophthora rot caused by Phytophthora megasperma Drechs. f. sp. glycinea Kuan and Erwin is a quantitative character of soybean [ Glycine max (L.) Merr.]. Recurrent selection can be an effective method of improving soybean populations for quantitative characters. The objective of our study was to evaluate the use of recurrent selection by S 1 ‐line evaluation for the development of a soybean population with improved tolerance to phytophthora rot. An intermated population, designated PMGT, was developed from 10 high‐yielding lines and cultivars from Maturity Groups I to IIl with moderate or better tolerance levels. Each cycle of selection of 1 year included the growing of S 0 plants in Puerto Rico during the winter to obtain S 1 lines, evaluation of the S 1 ‐lines for tolerance in the greenhouse and in a field nursery, selection of the most tolerant lines before flowering, and recombination of selected lines. Progress from selection was evaluated by comparing the mean performance of the parents for the cycle 0, 1, 2, and 3 populations in the greenhouse using the myceliuminoculum‐layer method and in a field nursery using visually rated hill plots. There was a significant linear improvement in mean tolerance score from cycle 0 to 3. Total realized gain was 21% when evaluated in the greenhouse and 10% when evaluated in the field. Genetic improvement in the population indicated that recurrent selection by S 1 ‐line evaluation is an effective method for improving populations for tolerance to phytophthora rot. The success of selection by S 1 ‐line evaluation indicated that early‐generation testing can be effective for determining the level of tolerance to phytophthora rot.