Diversification of Genes Encoding Granule-Bound Starch Synthase in Monocots and Dicots Is Marked by Multiple Genome-Wide Duplication Events

Starch is one of the major components of cereals, tubers, and fruits. Genes encoding granule-bound starch synthase (GBSS), which is responsible for amylose synthesis, have been extensively studied in cereals but little is known about them in fruits. Due to their low copy gene number, GBSS genes have been used to study plant phylogenetic and evolutionary relationships. In this study, GBSS genes have been isolated and characterized in three fruit trees, including apple, peach, and orange. Moreover, a comprehensive evolutionary study of GBSS genes has also been conducted between both monocots and eudicots. Results have revealed that genomic structures of GBSS genes in plants are conserved, suggesting they all have evolved from a common ancestor. In addition, the GBSS gene in an ancestral angiosperm must have undergone genome duplication ∼251 million years ago (MYA) to generate two families, GBSSI and GBSSII. Both GBSSI and GBSSII are found in monocots; however, GBSSI is absent in eudicots. The ancestral GBSSII must have undergone further divergence when monocots and eudicots split ∼165 MYA. This is consistent with expression profiles of GBSS genes, wherein these profiles are more similar to those of GBSSII in eudicots than to those of GBSSI genes in monocots. In dicots, GBSSII must have undergone further divergence when rosids and asterids split from each other ∼126 MYA. Taken together, these findings suggest that it is GBSSII rather than GBSSI of monocots that have orthologous relationships with GBSS genes of eudicots. Moreover, diversification of GBSS genes is mainly associated with genome-wide duplication events throughout the evolutionary course of history of monocots and eudicots

Defects segmentation on 'Golden Delicious' apples by using colour machine vision

A method based on colour information is proposed to detect defects on 'Golden Delicious' apples. In a first step, a colour model based on the variability of the normal colour is described. To segment the defects, each pixel of ail apple image is compared with the model. If it matches the pixel, it is considered as belonging to healthy tissue, otherwise as a defect. Two other steps refine the segmentation, using either parameters computed on the whole fruit, or values computed locally. Some results are shown and discussed. The algorithm is able to segment a wide range of defects. (C) 1998 Elsevier Science B.V. All rights reserved

Defect segmentation on 'Jonagold' apples using colour vision and a Bayesian classification method

This paper shows how the information enclosed in a colour image of a bi-colour apple can be used to segment defects. A method to segment pixels, based on a Bayesian classification process, is proposed. The colour frequency distributions of the healthy tissue and of the defects were used to estimate the probability distribution of each class. The results showed that most defects, namely bitter pit, fungi attack, scar tissue, frost damages, bruises, insect attack and scab, are segmented. However, russet was sometimes confused with the transition area between ground and blush colour. (C) 1999 Elsevier Science B.V. All rights reserved

Sélection de variétés d'oignon (Allium cepa L.) adaptées au nord de la Côte d'Ivoire

Selection of Varieties Onion (Allium cepa L.) Adapted to the North of Ivory Coast. Sixteen varieties of onion from the collection of the National Agronomical Research Center were evaluated on the basis of their performance in the North of Ivory Coast, during the agricultural season 1998- 1999. This evaluation was made in the presence of a local control, Violet de Galmi, at the station of production of onion seeds of the Rural Development Support National Agency. Varieties Rouge de Tana, RCS1903, RCS2211 and RCS2302 gave a higher rate of healthy bulbs (64.07% on average) than the others. For the total yield, varieties RCS1903, RCS2211 and RCS2302 produced more (18.18 t/ha on average) than Violet de Galmi (14.58 t/ha). The latter was more productive than Rouge de Tana (12.56 t/ha). However only the purple variety, Rouge de Tana had a high content of dry matter (20.86%) and was good preserved with nearly 95% of healthy bulbs after 3 months of storage, like the local control. Significant correlations appeared between the various studied characters. The most significant correlation was observed between the date of harvest and the percentage of layering at 100 days (r= -0.858); and the rate of healthy bulbs after 3 months of storage and the content of dry matter (r= 0.847)