AOBPreview originally published online on March 22, 2004
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Annals of Botany 93: 555-566, 2004
© 2004 Annals of Botany Company
Seed Coat Microsculpturing Changes during Seed Development in Diploid and Amphidiploid Brassica Species
1 Key Laboratory of MOE for Plant Developmental Biology, College of Life Sciences, Wuhan University, Wuhan, 430072, China, 2 College of Medicine and Life Sciences, Jianghan University, Wuhan, 430056, China and 3 Oil Crops Research Institute and The Chinese Agricultural Academy of Sciences, Wuhan, 430062, China
* For correspondence. E-mail jbwang{at}whu.edu.cn
Received: 12 September 2003; Returned for revision: 5 December 2003; Accepted: 19 January 2004 Published electronically: 22 March 2004
• Background and Aims Seed coat morphology is known to be an excellent character for taxonomic and evolutionary studies, thus understanding its structure and development has been an important goal for biologists. This research aimed to identify the developmental differences of seed coats between amphidiploids and their putative parents in Brassica.
• Methods Scanning electron microscope (SEM) studies were carried out on six species (12 accessions), three amphidiploids and their three diploid parents.
• Key Results Twelve types of basic ornamentation patterns were recognized during the whole developmental process of the seed coat. Six types of seed coat patterns appeared in three accessions of Brassica rapa, five types in B. oleracea, B. nigra and B. carinata, seven types in B. napus, and eight types in B. juncea. There was less difference among seed coat patterns of the three accessions of B. rapa. The reticulate and blister types were two of the most common patterns during the development of seeds in the six species, the blister-pimple and the pimple-foveate patterns were characteristic of B. rapa, and the ruminate of B. oleracea and B. nigra. The development of seed coat pattern in amphidiploids varied complicatedly. Some accessions showed intermediate patterns between the two putative parents, while others resembled only one of the two parents.
• Conclusions The variation in the patterns of seed coat development could be used to provide a new and more effective way to analyse the close relationship among amphidiploids and their ancestral parents.
Key words: Brassica, amphidiploids, diploids, SEM, seed coat microsculpturing, seed coat development, evolutionary implication.