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 Google Scholar Google Scholar Articles by Marani, A. Articles by Avieli, E. Search for Related Content PubMed Articles by Marani, A. Articles by Avieli, E. Agricola Articles by Marani, A. Articles by Avieli, E.

Heterosis During the Early Phases of Growth in Intraspecific and Interspecific Crosses of Cotton¹

The performance of interspecific and intraspecific F₁ hybrids of Gossypium hirsutum and G. barbadense planted on two different dates was investigated. The interspecific crosses showed significant heterosis for percentage and time of germination, leaf number, and date of square formation when planted on the first planting date, and for plant height, LAI, and dry matter weight for both planting dates. The G. barbadense intraspecific cross exhibited a higher degree of heterosis than the G. hirsutum one for germination and dry matter weight when planted on the first planting date.

The traits exhibiting significant estimates of heterosis for early planting, but not for late planting, were those associated with the early phases of plant growth. The differences stemming from planting dates were probably due to the low temperature that prevailed after the first planting, since the temperature after the second planting was close to the optimum. We concluded that F₁ hybrids have greater phenotypic stability than their parents when confronted with varying temperature conditions. This condition probably results from their heterosis for seedling growth rate under suboptimal temperature regimes.

Key Words: Gossypium • Planting dates • F₁ hybrids • Germination • Leaf number • LAI • Plant height • Dry matter weight

² Associate Professor, Department of Field and Vegetable Crops, and former Graduate Student (Present address: Laboratory of Soil and Water, Yotvata, Doar Eilot).

Received for publication June 19, 1972.