Comparative anatomy of tendril and fruit stalk in Curcubitaceae Juss. from Nigeria

Comparative anatomy of the fruit stalk and tendril of nine (9) species representing 8 genera of Cucurbits from Nigeria has been carried out to complement the existing taxonomic data on the family. Fresh plant materials from representative members of the genera Zehneria, Luffa, Momordica, Coccinnia, Telfairia, Cucurbita, Lagenaria and Cucumis collected from the wild during field trips to various parts of Nigeria were used for this study. The specimens were wax embedded, sectioned, stained and photographed with Leitz Diaplan photomicroscope fitted with Leica WILD MPS 52 camera. The findings of this study showed that there are similarities and variations in the shape, number and size of vascular bundles, nature of epidermis, layers and nature of sclerenchymatuous, chllenchymatuous and chlorenchymatuous cells in the fruit stalk  and tendril could be used to delimit the species of Cucurbitaceae in Nigeria. The variation in number and layers of these tissues among the species studied include vascular bundles (4 – 22 in fruit stalk, 4 – 10 in tendril), sclerenchymatuous cells (1 -8 layers in both tendril and fruit stalk), chlorenchymatuous cells (1 – 8 layers in both tendril and fruit stalk) and  collenchymatuous cells (1 – 6 layers in friut stalks, 2 – 6 layers in tendrils). Druses and prismatic crystals were observed among the species and the taxonomic implications of these features are discussed and represent the first report on the anatomy of fruit stalk of these cucurbits from Nigeria.© 2015 International Formulae Group. All rights reserved.Keywords: Anatomy, Cucurbitaceae, fruit stalk, Parenchyma, Sclerenchyma, tendri

Promising High-Yielding Tetraploid Plantain-Bred Hybrids in West Africa

The devastating threat of black leaf streak disease caused by Pseudocercospora fijiensis on plantain production in West Africa spurred the development of resistant hybrids. The goal of this research and development (R&D) undertaken was assessing the development and dissemination of two plantain hybrids PITA 3 and FHIA 21 bred in the 1980s by the International Institute of Tropical Agriculture (IITA, Nigeria) and the Fundaci ́on Hondureña de Investigacion Agŕıcola (FHIA, Honduras), respectively. In Cote d’Ivoire, plantain growers selected PITA 3 and FHIA 21 based on their improved agronomic characteristics and, between 2012 and 2016, they were massively propagated and distributed to farmers in Benin, Burkina Faso, Cote d’Ivoire, and Togo under the West Africa Agricultural Productivity Program (WAAAP) coordinated by the West and Central Africa Council for Agricultural Research and Development (CORAF). In 2016, the Centre National de Recherche Agronomique in Cote d’Ivoire included the hybrids in the improved cultivar directory. This R&D activity illustrates how three decades of crossbreeding, selection, and distribution led to local acceptance. It also highlights how a CORAF-led partnership harnessed CGIAR research for development. The dissemination and acceptance of these plantain hybrids will enhance the sustainable intensification in plantain-based farming systems across the humid lowlands of West and Central Africa

Morphological and Anatomical Studies on Trichosanthes cucumerina L. (Cucurbitaceae)

Studies on morphological, anatomical and proximate characteristics of Trichosanthes cucumerina L. (Cucurbitaceae) was carried out using morphological observation and microtomy in order to determine the relationship between this species and other cucurbits and complement the existing data on the taxon. T. cucumerina is a climber that grows up to 30m tall. The leaves are persistent partly ovate, trilobate to heptalobate, slightly hairy to densely hairy with glandular trichomes and non-glandular trichomes (2–5 celled, with a prominent flattened disk of two rows of cells). Tendril bifid, ovary consists of 3 syncarpous carpels and fruits 23.0 – 56.4 cm long. The species is hypostomatic with mainly anomocytic and tetracytic stomata and the epidermal cells appeared irregular in shape. Stem, peduncle, and tendril were angled with 5 – 13 bicollateral vascular bundles in open rings. The petiole and the midrib comprised 1 – 3 accessory vascular bundles. The sclerenchymatous cells were continuous or non-continuous. The tendril and stem have hollow pith. The similarity in morphological and anatomical features of this species and other members of cucurbits depicts taxonomic and evolutionary relationship among them, however; the type of trichomes we observed suggests that this species could be T. cucumerina var. anguina and not T. cucumerina. Further studies using electron microscope is therefore needed to affirm this finding

Comparative morphoanatomical studies of south eastern Nigerian representatives of Oldenlandia L. (Rubiaceae)

Leaf and stem anatomical structure of the four Oldenlandia L. (O. affinis (Roem. & Schult.) DC., O. corymbosa L., O. herbacea (Linn.) Roxb., and O. lancifolia (Schumach) DC.) from some parts viz. Ogbokor (Edo State), Obiga-Asa (Abia State), IITA staion Onne (Rivers State), and Agricultural farm Uniport (Rivers State) Nigeria were examined by light microscopy. The epidermal cells are pentagonal to polygonal with straight, curved or wavy anticlinal walls, and paracytic stomata. All the species have dorsiventral leaf with the leaf vein vascular bundles embedded in the spongy mesophyll. The midribs vascular bundles form an arc enclosed by parenchymatous endodermal cells. O. herabcea is amphistomatic while the other species are hypostomatic. Raphide bundles were seen only in the lamina of O. corymbosa. Tuft hair is absent in O. herbacea but occurred on the adaxial leaf surfaces of O. affinis, O. corymbosa, and O. diffusa. The stem of O. diffusa is terete while other species have quadrangular stem. Papillae occurred on the adaxial epidermis of O. affinis and O. corymbosa. The stem pith thickness (PT)/cortical thickness (ET) ratio varied among the species. Notable diagnostic features in these species include the PT/ET ratio, layers of cortex in the stem, occurrence of tuft hairs on the leaf veins and surface, presence or absence of raphides and papillose, layer of abaxial and adaxial cortex in the midrib, and amphistomatatic or hypostomatic leaf

Carotenoids in Cassava (<em>Manihot esculenta</em> Crantz)

Cassava is produced globally and consumed as an important staple in Africa for its calories, but the crop is deficient in micronutrients such as vitamin A. Pro-vitamin A carotenoids including β-carotene are precursors of vitamin A in the human body. Carotenoids are generally associated with colors of fruits and vegetables. Although most cassava varieties have white tuberous roots and generally accepted, naturally; some cassava roots are colored yellow and contain negligible amounts of vitamin A. Several genes have been identified in the carotenoids biosynthesis pathway of plants, but studies show that Phytoene synthase 2 (PSY2), lycopene epsilon cyclase, and β-carotene hydroxylase genes have higher expression levels in yellow cassava roots. So far, the PSY2 gene has been identified as the key gene associated with carotenoids in cassava. Some initiatives are implementing conventional breeding to increase pro-vitamin A carotenoids in cassava roots, and much success has been achieved in this regard. This chapter highlights various prediction tools employed for carotenoid content in fresh cassava roots, including molecular marker-assisted strategies developed to fast-track the conventional breeding for increased carotenoids in cassava