TDZ AND 4-CPPU in Gamborg B5 salts with MS vitamins doubles embryogenic 191 response from male flowers of EA-AAA banana.

Conventionally, auxins have been used in MS medium in combination or without purine-based cytokinins for induction of embryogenesis in EA-AAA banana (Musa spp.). Besides, low embryogenic response, it has been rare for more than two cultivars to respond similarly to a single treatment. This study investigated the efficacy of urea-type cytokinins, N-phenyl-N’-1,2,3-thidiazol-5-ylurea (TDZ) and N-(2-chloro-4-pyridyl)-N'-phenylurea (4-CPPU); and salt formulations, Chu (N6), Eriksson, Gamborg B5, MS, Nitsch, NLN, SH and White for embryogenic callus induction in different EA-AAA banana cultivars. Immature male flowers of cultivars Mpologoma, Mbwazirume, Nakabululu, Nakinyika and Nfuuka were cultured on callus induction medium, supplemented with different TDZ and 4-CPPU combinations. Most of the cultivars had embryogenic response to the medium with 10μM TDZ+10μM CPPU. Cultivar Nakabululu recorded 22.2% embryogenic response, followed by Mwazirume (5.7%), Nakinyika (5.3%) and Mpologoma (4.6%). Cultivar Nfuuka had 9.1% embryogenic response on 15μM TDZ+15μM CPPU. When cultivars Mpologoma and Nakinyika were cultured on the same medium containing 10μM TDZ+10μM CPPU, but the MS salts substituted with the other salt formulations, their cultures recorded 11.4 and 8.3% embryogenic response, respectively to Gamborg B5 salts; which was almost twice their response to MS medium. The results suggested that TDZ and 4-CPPU, particularly in Gamborg B5 salt formulation, could increase percentage of embryogenic callus induced from male flowers of EA-AAA banana cultivars, and would improve plant regeneration and consequently help in the process of genetic improvement of EA-AAA banana.Key Words: Cytokinins, embryogenic response, Musa spp., Thidiazuro

Transient expression of ß-glucuronidase in recalcitrant Ugandan sweetpotato and putative transformation with two cry genes.

Sweetpotato (Ipomoea batatas Lam.) has high potential to contain hunger, malnutrition and poverty in sub-Saharan Africa (SSA), since it gives early yield with few inputs. However, productivity of the crop in Africa is very low due to various challenges, such as severe viral diseases and increasing attacks by sweetpotato weevils, Cylas puncticollis and C. brunneus. Effective resistance to weevils has not been identified in the sweetpotato gene pool. On the other hand, the weevil-resistance genes, cry7Aa1 and cry3Ca1 were assembled into a plasmid vector for use in genetic transformation of African sweetpotato cultivars. The parameters for efficient transfer of these genes and the conditions for de novo regeneration optimised in preliminary studies were used in the genetic transformation of Ugandan landrace ‘Kyebandula’ with Agrobacterium tumefaciens EHA 105 harbouring the plasmid pCIP84, which contains cry7Aa1, cry3Ca1 and nptII in its T-DNA. Fifty-four percent of the explants formed adventitious buds. With a mean of 7 buds formed per explant, 6.0% explants formed shoots with a mean of one shoot per explant for those explants that formed shoots on medium containing 50 mg L-1 kanamycin as a selection agent. PCR analysis using primers for cry7Aa1 showed that the transformation efficiency could be as high as 2%. These data highlight the potential of genetic transformation in transferring resistance genes and pave way for enhancement of food security through production of adapted sweetpotato weevil resistant cultivars.Key Words: Agrobacterium tumefaciens, b-glucuronidase, Ipomoea batata

REACTION OF Musa balbisiana TO BANANA BACTERIAL WILT NFECTION

Banana bacterial wilt ( Xanthomonas campestris ) is an emerging disease of bananas in Uganda. All banana cultivars grown are susceptible. Musa balbisiana , a wild banana relative exhibits a progenitor like resistance type reaction to banana bacterial wilt infection. The negative M. balbisiana disease reaction suggests it could be used to improve banana resistance to banana bacterial wilt disease. Screenhouse and field experiments were used to characterise the reaction of M. balbisiana to banana bacterial wilt infetion. Psang awak, a reference susceptible cultivar was used as a positive control. No disease development on M. balbisiana under field and controlled conditions was observed. In general, as early as two weeks after inoculation, significant differences (P<0.05) were observed between M. balbisiana and the susceptible banana cultivar, Psang awak (ABB). Time course analysis of the possible role of Pathogenesis related protein 2 (PR-2), Phenyl alanine ammonia lyase (PAL), Non-expressor of pathogenesis related gene (NPR1) genes in Musa balbisiana resistance reactions, revealed that only NPR1 was expressed 15 days after inoculation with X. campestris at 108 dosage. The expression of NPR1, a marker gene of the systemic acquired resistance plant defence system provides preliminary evidence that this may be the major form of resistance in Musa balbisiana to bacterial wilt infection.Le fl\ue9trissement bact\ue9rien du bananier ( Xanthomonas campestris ) est une maladie \ue9mergente en Uganda, o\uf9 tous les cultivars en sont susceptibles. Musa balbisiana , un bananier relatif sauvage manifeste un type de r\ue9action de r\ue9sistance prog\ue9nitrice \ue0 l\u2019infection due au fl\ue9trissement bact\ue9rien. La r\ue9action n\ue9gative de M. balbisiana \ue0 la maladie sugg\ue8re que ceci pourrait \ueatre utilis\ue9 pour am\ue9liorer la r\ue9sistance du bananier cette maladie. Des essais en serre et en champs \ue9taient conduits pour caract\ue9riser la r\ue9action de M. balbisiana \ue0 l\u2019infection du bananier par le fl\ue9trissement bact\ue9rien. Le Psang awak, un cultivar susceptible de r\ue9ference \ue9tait utils\ue9 comme t\ue9moins positif. Aucun signe de d\ue9veloppement de la maladie n\u2019\ue9tait observ\ue9 sur M. balbisiana dans les deux milieux en champs et en serre. En g\ue9n\ue9ral, des diff\ue9rences significatives (P<0.05) \ue9taient observ\ue9es plus t\uf4t avant deux semaines apr\ue8s inoculation entre M. balbisiana et le cultivar de bananier susceptible, Psang awak (ABB). L\u2019analyse du temps de d\ue9roulement du r\uf4le possible de la pathogen\ue8se li\ue9e \ue0 la prot\ue9ine 2 (PR-2), \ue0 la Ph\ue9nyl alanine ammonia lyase (PAL), \ue0 la non-expression de la pathogen\ue8se li\ue9e au g\ue9ne (NPR1) de r\ue9sistance exprim\ue9e par Musa balbisiana, a r\ue9v\ue9l\ue9 que seulement NPR1 s\u2019\ue9tait exprim\ue9 15 jours apr\ue8s inoculation du X. campestris au dosage de 108. L\u2019expression de NPR1, un marqueur de g\ue8ne de r\ue9sistance acquis du syst\ue8me de d\ue9fence des plantes fournit une \ue9vidence que ceci serait une forme majeur de r\ue9sistance du Musa balbisiana \ue0 l\u2019infection du fl\ue9trissement bact\ue9rien

Induction of somatic embryogenesis in recalcitrant sweetpotato (Ipomoea batatas L.) cultivars

Genetic transformation is considered as one of the most promising options for improvement of crop traits. Current transformation methods for sweetpotato depend on plant regeneration through organogenesis or somatic embryogenesis. Somatic embryogenesis and plant regeneration at a high frequency has been  restricted to a few sweetpotato varieties. Three auxins namely: 2,4-dichlorophenoxyacetic acid (2,4-D),  4-fluoroamphetamine (4-FA) and 4,5-trichlorophenoxyacetic acid (2,4,5-T) were investigated in this study for enhancing somatic embryogenesis from various plant organs of recalcitrant African sweetpotato cultivars.  2,4-D was found to be the best (p . 0.05) for induction of embryogenic callus. Cultivar Bwanjule had the highest  (20.2%) embryogenic callus frequency among the five African cultivars tested. The highest number of plants in this study was regenerated from the non-African cultivar variety Jonathan on media supplemented with 0.2 mg Zeatin. The emergence of roots from callus of recalcitrant Ugandan cultivars and the comparable high embryogenic responses in this work demonstrate the potential for regenerating plants from African  cultivars that have not been regenerated before. The regeneration of roots in this work could be useful for the initiation of root cultures. The most important application of this work is in genetic transformation of sweet potato, particularly for improvement of resistance to weevils.Key words: Embryogenesis, plant growth regulators, plant regeneration, Ipomoea batatas

Religious beliefs and entrepreneurial behaviours in Africa: a case study of the informal sector in Uganda

Religion plays a major role in Africa’s polity and its influence on the business landscape of the continent has been acknowledged in literature. This study contributes to the discourse by investigating and explaining how religious beliefs shape entrepreneurial behaviours in Uganda’s informal sector. Using a qualitative methodology, we explored how entrepreneurs in the context use or adopt religious beliefs in their entrepreneurial activities. By spanning a diverse set of entrepreneurial activities in the informal sector- food vendors, fabricators, hawkers, and recyclers among others, we conducted 49 in-depth interviews. Our findings reveal that the entrepreneurs relied on their religious beliefs in defining and coping with a penurious context. Further to this, we explain how religious beliefs galvanize business behaviours and calibrate the entrepreneurial identities of respondents in the context. To facilitate future work, the study highlights how knowledge gaps in the cultural and social setup of the informal economy will produce new insights in entrepreneurship research. It concludes by guiding policy makers and educators to engage and involve faith based institutions in the entrepreneurship promotion agenda

TDZ AND 4-CPPU IN GAMBORG B5 SALTS WITH MS VITAMINS DOUBLES EMBRYOGENIC RESPONSE FROM MALE FLOWERS OF EA-AAA BANANA

Conventionally, auxins have been used in MS medium in combination or without purine-based cytokinins for induction of embryogenesis in EA-AAA banana ( Musa spp.). Besides, low embryogenic response, it has been rare for more than two cultivars to respond similarly to a single treatment. This study investigated the efficacy of urea-type cytokinins, N-phenyl-N\u2019-1,2,3-thidiazol-5-ylurea (TDZ) and N-(2-chloro-4-pyridyl)-N\u2019-phenylurea (4-CPPU); and salt formulations, Chu (N6), Eriksson, Gamborg B5, MS, Nitsch, NLN, SH and White for embryogenic callus induction in different EA-AAA banana cultivars. Immature male flowers of cultivars Mpologoma, Mbwazirume, Nakabululu, Nakinyika and Nfuuka were cultured on callus induction medium, supplemented with different TDZ and 4-CPPU combinations. Most of the cultivars had embryogenic response to the medium with 10\ub5M TDZ+10\ub5M CPPU. Cultivar Nakabululu recorded 22.2% embryogenic response, followed by Mwazirume (5.7%), Nakinyika (5.3%) and Mpologoma (4.6%). Cultivar Nfuuka had 9.1% embryogenic response on 15\ub5M TDZ+15\ub5M CPPU. When cultivars Mpologoma and Nakinyika were cultured on the same medium containing 10\ub5M TDZ+10\ub5M CPPU, but the MS salts substituted with the other salt formulations, their cultures recorded 11.4 and 8.3% embryogenic response, respectively to Gamborg B5 salts; which was almost twice their response to MS medium. The results suggested that TDZ and 4-CPPU, particularly in Gamborg B5 salt formulation, could increase percentage of embryogenic callus induced from male flowers of EA-AAA banana cultivars, and would improve plant regeneration and consequently help in the process of genetic improvement of EA-AAA banana.Conventionnellement, les auxines ont \ue9t\ue9 utilisees dans le medium MS en combinaison avec ou sans cytokinines \ue0 base de purine pour induction de l\u2019embryogen\ue8se dans la banane EA-AAA ( Musa spp.). En plus d\u2019une faible r\ue9ponse embryog\ue9nique, il a \ue9t\ue9 rare pour plus de deux cultivars de r\ue9pondre de fa\ue7on similaire \ue0 un seul traitement. Cette \ue9tude a \ue9t\ue9 conduite pour \ue9valuer l\u2019efficacit\ue9 des cytokinines de type urea, N-phenyl-N\u2019-1,2,3-thidiazol-5-ylurea (TDZ) et N-(2-chloro-4-pyridyl)-N\u2019-phenylurea (4-CPPU)\ua0; et les formulations du sel, Chu (N6), Eriksson, Gamborg B5, MS, Nitsch, NLN, SH et blanc pour l\u2019 induction du callus embryog\ue9nique dans diff\ue9rents cultivars de banane EA-AAA. Des cultivars Mpologoma des fleurs males immatures Mbwazirume, Nakabululu, Nakinyika et Nfuuka \ue9taient cultiv\ue9s sur le medium d\u2019induction du callus, suppl\ue9ment\ue9e avec diff\ue9rentes combinaisons de TDZ et 4-CPPU. La plupart des cultivars avaient une r\ue9ponse embryog\ue9nique au medium avec 10\ub5M TDZ+10\ub5M CPPU. Le cultivar Nakabululu a r\ue9alis\ue9 22.2% de r\ue9ponse embryog\ue9nique, suivi de Mbwazirume (5.7%), Nakinyika (5.3%) et Mpologoma (4.6%). Le cultivar Nfuuka avait 9.1% de r\ue9ponse embryog\ue9nique sur 15\ub5M TDZ+15\ub5M CPPU. Lorsque les cultivars Mpologoma et Nakinyika \ue9taient cultiv\ue9s sur le m\ueame medium contenant 10\ub5M TDZ+10\ub5M CPPU, mais les sels MS substitu\ue9s par d\u2019autres formulations de sels, leurs cultures ont enregistr\ue9 11.4 et 8.3% de r\ue9ponses embryog\ue9niques, respectivement, aux sels Gamborg B5; qui faisait presque le double de leur r\ue9ponse au medium MS. Les r\ue9sultats ont sugg\ue8rent que TDZ et 4-CPPU, particuli\ue8rement dans la formulation du sel Gamborg B5, pourrait augmenter le pourcentage induit du callus embryog\ue9nique des fleurs males des cultivars de banane EA-AAA et pourrait am\ue9liorer la r\ue9g\ue9n\ue9ration des plants et en cons\ue9quence aider dans le processus de l\u2019am\ue9lioration g\ue9n\ue9tique de la banane EA-AAA

Agrobacterium mediated transformation of banana (Musa sp.) cv. Sukali Ndiizi (ABB) with a modified Carica papaya cystatin (CpCYS) gene

Conventional banana breeding for pest and disease resistance is a very difficult and slow process due to the limited sources of resistance, sterility of cultivated banana varieties, high polyploidy levels, long cropping cycle and the lack of rapid screening methods.Molecular breeding using the transgenic approach with candidate genes such as cystatins offers an alternative method to banana improvement. Cystatin proteins inhibit the activity of cysteine proteases responsible for the breakdown of dietary proteins in the gut of many pests including nematodes resulting in protein deficiency. In this study, the papaya cystatin gene was introduced into the banana genome. Embryogenic cell suspension (ECS) cultures of the banana cultivar Sukali Ndiizi (ABB) were used as explants material for the successful transformation of banana. The Carica papaya cystatin gene (CpCYS-Mut89) previously modified to improve its inhibitory potential against banana pests was introduced into this cultivar using Agrobacterium tumefaciens, strain LBA4404 and the gus reporter gene was used to observe successful transformation process. We report the successful protocol for routine transformation of this cultivar, which was completed in six months with plant regeneration observed at a frequency of 23%. An additional four months was required to multiply the regenerant lines in order to have at least 20 plants per line for downstream challenging studies. Putatively transgenic plants were analyzed by PCR using hpt and CpCYS - Mut89 specific primers to confirm the presence of trans genes. Out of 28 selected lines, 27 were positive for both hpt and CpCYS - Mut89 transgenes giving 96.4 % transformation efficiency. Fivelines were then selected on the basis of putative PCR positives and a Southern b lot analysis gave hybridization signals with 1 to 4 copy number integration patterns characteristic of Agrobacterium mediated transformation. These results confirm stable gene integration in East African banana cultivar cv. Sukali Ndiizi (genome group ABB) through an efficient Agrobacterium - mediated transformation protocol described for routine use in future improvement of this crop with genes of economic importance