Association between vitamin content, plant morphology and geographical origin in a worldwide collection of the orphan crop Gynandropsis gynandra (Cleomaceae).

MAIN CONCLUSION: The variability in nutrient content and morphology in Gynandropsis gynandra is associated with the geographic origin of the accessions and provides a basis for breeding for higher levels of vitamin C, carotenoids or tocopherols in higher-yielding cultivars. We examined the variation in carotenoids, tocopherols and ascorbic acid as well as morphological traits in a worldwide germplasm of 76 accessions of the orphan leafy vegetable Gynandropsis gynandra (Cleomaceae) using greenhouse experiments and high-performance liquid chromatography analysis. The levels of carotenoids and tocopherols accumulating in the leaves varied significantly across accessions and were linked with the geographical origin and morphological variation. The main carotenoids included lutein, ß-carotene, α-carotene and violaxanthin. A twofold to threefold variation was observed for these compounds. The main tocopherols detected were α-tocopherol and γ-tocopherol with a 20-fold variation. A ninefold variation in vitamin C concentration and independent of geographical origin was observed. Overall, the accessions were grouped into three clusters based on variation in nutrient content and morphology. West African accessions were short plants with small leaves and with high tocopherol contents and relatively low carotenoid contents, Asian accessions were short plants with broad leaves and with relatively low carotenoid and high tocopherol contents, while East-Southern African plants were tall with high contents of both carotenoids and chlorophylls and low tocopherol contents. Carotenoids were positively correlated with plant height as well as foliar and floral traits but negatively correlated with tocopherols. The absence of a significant correlation between vitamin C and other traits indicated that breeding for high carotenoids or tocopherols content may be coupled with improved leaf yield and vitamin C content. Our study provides baseline information on the natural variation available for traits of interest for breeding for enhanced crop yield and nutrient content in Gynandropsis gynandra.

Nutritional compound analysis and morphological characterization of spider plant (Cleome gynandra) - an African indigenous leafy vegetable.

Spider plant is among the important indigenous African leafy vegetables having the potential to contribute to food and nutritional security in sub-Saharan Africa. The main objective of this study was to quantify the mineral concentration, to identify and quantify glucosinolates and flavonoids in spider plant and further to characterize spider plant entries using important morphological traits. Thirty spider plant entries from different African countries, comprising of farmers' cultivars, gene bank accessions and advanced lines were grown in a field experiment and harvested for leaves, stems, flowers and siliques at different developmental stages. Five plant types based on the stem and petiole colorations were identified. Significant genotypic differences were shown for all the morphological traits except for 100 seed weight and silique weight. High mineral concentrations in the leaf tissue were observed especially for potassium, calcium, magnesium, phosphorus, iron, manganese and zinc. The aliphatic 3-hydroxypropyl glucosinolate was the main glucosinolate detected in all tissues with the highest concentrations in the reproductive organs. Glycosides of quercetin, kaempferol and isorhamnetin were the main flavonoids. Isorhamnetin glycosides were detected in trace amounts in both, leaves and inflorescences, while quercetin and kaempferol glycosides were the dominant flavonoids in the leaves and inflorescences, respectively. This knowledge of beneficial nutrient contents is an incentive for promoting spider plant consumption for improved human health while the morphological diversity analysis will be important for the further development of the spider plant germplasm.

Intra-plant floral variation in Cleome viscosa L. and its possible significance in breeding system.

Cleome viscosa L., an annual rainy season weed, is cosmopolitan in distribution. Two naturally growing populations of C. viscosa from Jammu, J & K, India have been studied for floral variation at an intra-plant level and its possible role in its life cycle. Plants of both the populations bear flowers which exhibit tremendous intra-plant variation in size (large and small) and sex (hermaphrodite, staminate and pistillate). The average number of flowers per plant varied significantly and so did their structural and functional details. Greater propensity, however, was towards hermaphroditism at both plant and flower levels. The large and small sized flowers differed in their morphology and reproductive features; the former were significantly larger than the latter. Anthesis, anther dehiscence and stigma receptivity were coupled in all flower types. This functional aspect along with the structural proximity between stamens at two lengths and pistil further facilitated self-pollination. However, conspicuous floral display attracted diverse pollinator fauna (Apis dorsata, Halictus albescens, Nomia curvipes and N. elliotii) which in turn mediated cross pollination. Nevertheless, each floral type contributed towards plant's fitness in its own way. Hermaphrodite flowers exhibited both self and cross pollination and assured survival by setting fruits and seeds with the large sized counterparts more productive. All these floral variations seemed to impart flexibility to the pollination system and provide fitness over the short flowering season.

Diversity in forms of C4 in the genus Cleome (Cleomaceae).

BACKGROUND AND AIMS: Cleomaceae is one of 19 angiosperm families in which C(4) photosynthesis has been reported. The aim of the study was to determine the type, and diversity, of structural and functional forms of C(4) in genus Cleome. Methods Plants of Cleome species were grown from seeds, and leaves were subjected to carbon isotope analysis, light and scanning electron microscopy, western blot analysis of proteins, and in situ immunolocalization for ribulose bisphosphate carboxylase oxygenase (Rubisco) and phosphoenolpyruvate carboxylase (PEPC). KEY RESULTS: Three species with C(4)-type carbon isotope values occurring in separate lineages in the genus (Cleome angustifolia, C. gynandra and C. oxalidea) were shown to have features of C(4) photosynthesis in leaves and cotyledons. Immunolocalization studies show that PEPC is localized in mesophyll (M) cells and Rubisco is selectively localized in bundle sheath (BS) cells in leaves and cotyledons, characteristic of species with Kranz anatomy. Analyses of leaves for key photosynthetic enzymes show they have high expression of markers for the C(4) cycle (compared with the C(3)-C(4) intermediate C. paradoxa and the C(3) species C. africana). All three are biochemically NAD-malic enzyme sub-type, with higher granal development in BS than in M chloroplasts, characteristic of this biochemical sub-type. Cleome gynandra and C. oxalidea have atriplicoid-type Kranz anatomy with multiple simple Kranz units around individual veins. However, C. angustifolia anatomy is represented by a double layer of concentric chlorenchyma forming a single compound Kranz unit by surrounding all the vascular bundles and water storage cells. CONCLUSIONS: NAD-malic enzyme-type C(4) photosynthesis evolved multiple times in the family Cleomaceae, twice with atriplicoid-type anatomy in compound leaves having flat, broad leaflets in the pantropical species C. gynandra and the Australian species C. oxalidea, and once by forming a single Kranz unit in compound leaves with semi-terete leaflets in the African species C. angustifolia. The leaf morphology of C. angustifolia, which is similar to that of the sister, C(3)-C(4) intermediate African species C. paradoxa, suggests adaptation of this lineage to arid environments, which is supported by biogeographical information.