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

This Article Figures Only Full Text 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 Google Scholar Articles by Shaimi, N. Articles by Faiz, C. A. PubMed Articles by Shaimi, N. Articles by Faiz, C. A. Agricola Articles by Shaimi, N. Articles by Faiz, C. A. Related Collections Other Grain Crops Plant Genetic Resources

SUMMER DORMANCY SYMPOSIUM

Summer Dormancy in Orchardgrass: Evaluation and Characterization through Ecophysiological and Genetic Studies

^a Institut National de la Recherche Agronomique (INRA), B.P. 415, Rabat, Morocco
^b INRA, UMR SYSTEM, 2 place Viala 34060 Montpellier, Cedex 1, France

^* Corresponding author (faizchawki{at}yahoo.fr).

Climatic change manifested by increasing summer drought necessitates the development of drought-tolerant forage grass cultivars. Summer dormancy is a major trait conferring drought survival and autumn recovery of perennial grasses in Mediterranean areas. Moroccan ecotypes of orchardgrass (Dactylis glomerata L.) expressed 67% greater degree of summer dormancy than tested cultivars except the highly dormant ‘Kasbah.’ Furthermore, summer dormancy was highly correlated with perenniality (r = 0.63, P < 0.01). However, summer dormancy was associated with low productivity. A breeding program was started to develop productive orchardgrass cultivars with high summer dormancy. Hybrids between high- and low-dormancy cultivars produced offspring with combinations of enhanced dormancy and biomass production indicating potential for breaking the negative dormancy-yield association. For example, Kasbah (dormant) x ‘Medly’ (summer-active) hybrids were 57% more dormant than Medly and 32% higher yielding than Kasbah. Genetic analysis of heritability and molecular markers will provide more information on the genetic control of summer dormancy. Results of crosses between contrasting populations of orchardgrass indicate potential for combining the desirable traits of summer dormancy and high annual herbage yield into an eventual cultivar.

Abbreviations: DM, dry matter • LAI, leaf area index • QTL, quantitative trait loci • SDI, summer dormancy index • S/Sp, summer:spring yield ratio for calculating SDI