Maturation of geranium (Pelargonium x hortorum Bailey) somatic embryos

Doctor of Philosoph

The role of amino acids on maturation and conversion of geranium somatic embryos

The effect of various concentrations of 4 amino acids (cysteine, glutamine, methionine and proline) on maturation and conversion of thidiazuron - induced somatic embryos were investigated. All the amino acids used improved maturation frequency, protein content and plantlet dry weight of converted embryos indicating a general improvement of the nutritive status of the somatic embryos. Addition of methionine, proline, cysteine(3mM) and glutamine (10 mM) in the maturation media also improved conversion frequency of somatic embryos. Inclusion of amino acids in a maturation media improves both morphological maturity and physiological maturity of geranium somatic embryos. This study shows the importance of inclusion of amino acids in a maturation media for improved somatic embryo quality.La pr\ue9sente \ue9tude porte sur l'effet des diff\ue9rentes concentrations de 4 acides amin\ue9s (cyst\ue9ine, glutamine, m\ue9thionine et proline) sur la maturation et la transformation de thidia zuron - embryons somatiques induits. Tous les acides amin\ue9s utilis\ue9s ont am\ue9lior\ue9 la fr\ue9quence de maturation, la teneur en prot\ue9ine et le poids sec des plantules des embryons transform\ue9s indiquant une am\ue9lioration g\ue9n\ue9rale de l'\ue9tat nutritif des embryons somatiques. L'addition des m\ue9thionine, proline, cyst\ue9ime (3mM) et glutamine (10mM) dans les milieux de maturation a aussi am\ue9lior\ue9 la fr\ue9quence de transformation des embryons somatiques. L'introduction des acides amin\ue9s dans les milieux de maturation am\ue9liore \ue0 la fois la maturit\ue9 morphologique et physiologique des embryons somatiques du geranium. Cette \ue9tude montre ainsi l'importance de l'inclusion des acides amin\ue9s dans les milieux de maturation afin d'am\ue9liorer la qualit\ue9 des embryons somatiques

The effects of sugars on maturation and conversion of geranium (Pelargonium x hortorum Bailey) embryos.

The effect of various concentrations of sucrose and glucose on maturation and conversion of geranium (Pelargonium x hortorum Bailey) somatic embryos was investigated at Guelph, Ontario, Canada in 1994 and 1995. Somatic embryos were induced on medium with 20 M thidiazuron for 3 days then matured on media with 3, 6 and 9 % sucrose or glucose, 21 days from the start of culture. Glucose (6 %) and sucrose (6 and 9 %) significantly improved maturation frequency of somatic embryos compared to 3 % sucrose. Sucrose at 6 and 9 % also reduced precocious germination of somatic embryos in culture. Glucose at 3 and 6 % and sucrose at 6 and 9 % both significantly increased protein content in somatic embryos compared to 3 % sucrose. Only 3 % glucose significantly improved conversion frequency while 6 % sucrose and 9 % of both sucrose and glucose reduced conversion frequency of somatic embryos. This study shows the importance of inclusion of sugars in the maturation of geranium somatic embryos. Transactions of the Zimbabwe Scientific AssociationVolume 72 1998, pp. 26-3

Traditional vegetables of northern KwaZulu-Natal, South Africa: has indigenous knowledge expanded the menu?

A survey was conducted on traditional vegetables in three districts of northern KwaZulu-Natal, South Africa. The objective was to determine which alien and native plant species were collected from the wild or cultivated for use as leafy vegetables. The survey documented 72 vegetable species of which nearly half were alien species. The majority of the vegetables were collected from the wild (56 species) and only 16 were cultivated. Alien species were preferred more extensively than native species (2.5 times more), despite the larger variety (larger choice) of the latter (38 native versus 34 alien species). Nearly 53% of traditional vegetables of alien origin belong to well-known vegetable families that are indigenous to the study area, suggesting that there is a classification system that allows people to explore new plant sources. This makes a case that Indigenous Knowledge Systems can expand the menu by incorporating newly introduced species. However, this also suggests that alien species, which are weedy and easily obtained around the home, is displacing native species as a major food source. Our findings also suggest that wild vegetables might have been predisposed for use due to their medicinal value.http://www.academicjournals.org/ajar/PDF/pdf2012/27Nov/Ntuli%20et%20al.pdfhttp://dx.doi.org/10.5897/AJAR11.219

Índice de área foliar, interceptação luminosa e acúmulo de forragem em pastagens de Cynodon spp. sob diferentes intensidades de pastejo Canopy characteristics and herbage accumulation of Cynodon spp. submitted to different grazing intensities

Avaliou-se o índice de área foliar (IAF), interceptação luminosa (IL) e acúmulo de matéria seca em três cultivares de Cynodon spp. (Tifton-85, Florakirk e Coastcross) submetidos a quatro intensidades de pastejo (5, 10, 15 e 20 cm) estabelecidas com ovinos em regime de lotação contínua. O delineamento experimental utilizado foi o de blocos completos casualizados com quatro repetições e parcelas sub-divididas, onde na parcela foram alocados os cultivares e na sub-parcela as intensidades de pastejo. Os maiores valores de IAF foram encontrados para Tifton-85. As taxas de acúmulo de matéria seca foram semelhantes em todos os tratamentos. Tifton-85 apresentou como amplitude ótima de uso condições de pasto que variaram de 5 a 15 cm. Para Florakirk essa amplitude foi até 20 cm e para Coastcross o limite foi superior a 20 cm. Diferentes cultivares apresentaram requerimentos variados de manejo de desfolha quando o objetivo foi o uso eficiente da luz e dos demais fatores de crescimento para elevados índices de utilização da forragem produzida.<br>Leaf area index (LAI), light interception and herbage accumulation were evaluated for three Cynodon spp. cultivars (Tifton-85, Florakirk and Coastcross) submitted to four grazing intensities (5, 10, 15 and 20 cm) established by sheep under a continuous stocking management. A complete randomised block design was used with four replications, with treatements in a split-plot arrangement. Grass cultivars were allocated to plots and grazing intensities to sub-plots. The largest values of LAI were observed for Tifton-85. Rates of dry matter accumulation were similar for all treatments. Tifton-85 presented a narrower optimal range for pasture conditions (5 to 15 cm) as compared to Florakirk (5-20 cm) and Coastcross (5-20+ cm). Different grass cultivars presented different grazing management requirements in situations where the efficient use of light and high levels of herbage utilisation were targeted