Plastid differentiation during androgenesis in albino and non-albino producing cultivars of barley (Hordeum vulgare L.) |
| |
Authors: | S Caredda C Doncoeur P Devaux R S Sangwan C Clément |
| |
Institution: | (1) Université de Reims Champagne Ardenne, UFR Sciences, Biologie et Physiologie Végétales, BP 1039; 51687 Reims Cédex 2, France E-mail: christophe.clement@univ.reims.fr, FR;(2) Florimond Desprez Ind., Section Biotechnologies, BP 41; 59242 Cappelle en Pévèle, France, FR;(3) Université de Picardie Jules Verne, Androgénèse et Biotechnologies, 33, rue Saint-Leu; 80039 Amiens, France, FR |
| |
Abstract: | In order to better understand androgenic albinism in barley, we compared plastid differentiation during anther culture in
two cultivars, an albino (spring cultivar Cork) and a non-albino (winter cultivar Igri) producing cultivar. The ultrastructure
of plastids and the relative amount of DNA containing plastids were followed in both cultivars during the androgenic process
and correlated with the proportion of regenerated chlorophyllous plantlets.
For androgenesis, anthers were collected at the uninucleate stage, during mid- or late-microspore vacuolation. At this stage
DNA was detected in 15.3 ± 2. 7% of microspore plastid sections in the winter cultivar Igri, compared to 1.7 ± 0.5% in the
spring cultivar Cork. In the winter cultivar Igri, starch was broken down after anther pretreatment but plastids divided rapidly
during anther culture and thylakoids developed in the stroma. Prior to regeneration, plastids contained 2.0 ± 0.2 thylakoids
per plastid and starch represented 26.1 ± 3.3% of the plastid volume. In the spring cultivar Cork, plastids followed a different
developmental pathway. After anther pretreatment, microspore plastids differentiated exclusively into amyloplasts, accumulating
starch and losing their thylakoids as well as their capacity to divide. This developmental pattern became progressively more
marked, so that by the end of anther culture plastids contained 0.5 ± 0.4 thylakoids per plastid and starch represented up
to 90.3 ± 4.3% of plastid volume. Following androgenesis, the response was similar in both cultivars except that the winter
cultivar Igri provided 87.8% of chlorophyllous plantlets compared to 99.7% albino plantlets in the cultivar Cork.
The results presented here suggest that the exclusive regeneration of albino plantlets in the spring cultivar Cork may be
due to degradation of microspore plastid DNA during early pollen development, preventing the plastids from differentiating
into chloroplasts under culture conditions.
Received: 13 March 2000 / Revision accepted: 6 June 2000 |
| |
Keywords: | Androgenesis Albinism Hordeum vulgare L Plastid differentiation Plastid DNA Pollen development |
本文献已被 SpringerLink 等数据库收录! |
|