HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Ehlers, J. D. Articles by Hall, A. E. Search for Related Content PubMed Articles by Ehlers, J. D. Articles by Hall, A. E. Agricola Articles by Ehlers, J. D. Articles by Hall, A. E.

Genotypic Classification of Cowpea Based on Responses to Heat and Photoperiod

Dep. of Botany and Plant Sciences, Univ. of California, Riverside, CA 92521-0124

^* Corresponding author (jehlers{at}ucracl.ucr.edu).

Heat and photoperiod influence reproductive development and yield of crop plants. In cowpea (Vigna unguiculata [L.] Walp.), genetic variation is present for heat tolerance and responses to photoperiod during different stages of reproductive development. A genotypic classification system had been developed based on responses to high temperature under long days. Further studies were needed under short and long days and hot and moderate temperatures to characterize genotypic variation for juvenility and photoperiod response and interactions with temperature. Forty-four contrasting cowpea genotypes were sown in the field with moderate (31.5/16.5°C day/night) and hot (38/22.5°C day/night) temperature long day environments and in glasshouses in hot (35/26°C day/night) or moderate (32/18°C day/night) temperatures under short (11 h 20 min at planting to 12 h 20 min after 30 d) and long (14 h 50 min at planting to 14 h 16 rain after 30 d) days, and these genotypes were evaluated for juvenility and photoperiod and temperature responses. The genotypes were classified into II groups based on photoperiod response (change in position of the first reproductive node or period to appearance of floral buds in long compared with short days), juvenility (minimum period for appearance of floral buds when grown under short days), and suppression of floral bud development and pod set under hot long days. This classification system will aid breeders and agronomists in their understanding of the genetic variation for these characteristics and in choosing genotypes with appropriate juvenility, photoperiod response, and heat tolerance for breeding and agronomy programs serving tropical and subtropical production environments.

Received for publication May 30, 1995.

This article has been cited by other articles:

				C.-D. Li, C. A. Fatokun, B. Ubi, B. B. Singh, and G. J. Scoles Determining Genetic Similarities and Relationships among Cowpea Breeding Lines and Cultivars by Microsatellite Markers Crop Sci., January 1, 2001; 41(1): 189 - 197. [Abstract] [Full Text] [PDF]

				A. M. Ismail, A. E. Hall, and J. D. Ehlers Delayed-Leaf-Senescence and Heat-Tolerance Traits Mainly Are Independently Expressed in Cowpea Crop Sci., July 1, 2000; 40(4): 1049 - 1055. [Abstract] [Full Text]

				A. M. Ismail and A. E. Hall Reproductive-Stage Heat Tolerance, Leaf Membrane Thermostability and Plant Morphology in Cowpea Crop Sci., November 1, 1999; 39(6): 1762 - 1768. [Abstract] [Full Text]

				A.G. Gillaspie Jr., R.J. Goenaga, S. Torres, and E. Peregrine Identification of suitable seed regeneration sites for photoperiod-sensitive cowpea germplasm Crop Sci., September 1, 1999; 39(5): 1513 - 1515. [Abstract] [Full Text]