Browsing by Author "Sseremba, Godfrey"
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Item Accuracy of using leaf blade length and leaf blade width measurements to calculate the leaf area of Solanum aethiopicum Shum group(Heliyon, 2018) Nakanwagi, Mildred Julian; Sseremba, Godfrey; Nahamya, Pamela Kabod; Masanza, Michael; Balyejusa Kizito, ElizabethLeaf area is an important parameter when determining growth response under normal as well as stressed environments. No attempt had been made to come up with an affordable but accurate alternative of measuring leaf size in research neglected leafy vegetable crops. Other techniques such as use of leaf area meters are either destructive, expensive or both. A study was conducted to determine leaf area in like-shaped leaves of research neglected crop plants, taking case of S. aethiopicum Shum group (SAS) germplasm. Data was collected on 552 individual plants (including pure lines and hybrids) at eight weeks after planting where a third fully open leaf from top of each plant was considered. Leaf blade length (LBL) and leaf blade width (LBW) were linearly measured while leaf area (LA) was measured using a leaf area meter. This was followed by correlation and regression analysis of LA with LBL, LBW, and LBL þ LBW. Correlation coefficients at p < 0.001 ranged between 0.84 and 0.92, 0.79 and 0.88, 0.86 and 0.95 for total germplasm, pure lines and hybrids, respectively. The coefficient of determination (R2) ranged between 0.72 and 0.92. The best prediction for LA was obtained with hybrid plants (LA ¼ -165.82 þ 5.38LBL þ 16.17LBW) at R2 of 92%. The implication is that we can accurately and affordably predict LA from duo measurements of LBL and LBW in SAS as well as in other crops having similar leaf shapes.Item Farmer preferred traits and genotype choices in Solanum aethiopicum L., Shum group(Journal of ethnobiology and ethnomedicine, 2021) Nakyewa, Brenda; Sseremba, Godfrey; Kabod, Nahamya Pamela; Rwothtimutung, Moses; Kyebalyenda, Tadeo; Waholi, Kenneth; Buteme, Ruth; Nakanwangi, Mildred Julian; Bishop, Gerard; Balyejusa Kizito, ElizabethSolanum aethiopicum L. is a nutrient dense African indigenous vegetable. However, advancement of its improved varieties that can increase productivity, household income, and food security has not been prioritized. Further still, studies on some of the crops that have been worked have indicated that it is not a guarantee that the improved varieties will be accepted by the end users and therefore there is need to identify and profile what genotypes are of interest to farmers and their preferred traits through inclusive participatory evaluations. Methodology: Farmer participatory evaluations were conducted to profile farmers’ traits of interest and preferred genotypes. A total of 24 genotypes were established in three replications in 6 farms in 3 districts; Wakiso, Mukono, and Luwero as these are the major producing districts of the vegetable in Uganda. A total of 177 sex-disaggregated farmers were engaged in scoring the genotypes for pest, disease and drought tolerance, general appeal, leaf yield, leaf texture, and seed yield for best 10 genotypes under each variable. Results: Non-significant differences in trait (p > 0.05) and genotype preferences (p > 0.05) were obtained between men and women. The most desired farmer traits were seed and leaf yield, followed by pest and disease resistance. The overall preferred genotype in terms of disease and pest resistance, leaf yield, leaf texture, and seed yield were E12 followed by E11. Conclusion: Gender does not seem to influence farmer choices for the S. aethiopicum, Shum group, indicating an opportunity for single variety prototype advancement by breeders and dissemination by seed companies.Item Heritability of drought resistance in Solanum aethiopicum Shum group and combining ability of genotypes for drought tolerance and recovery(Scientia Horticulturae, 2018) Sseremba, Godfrey; Tongoona, Pangirayi; Eleblu, John; Danquah, Eric Yirenkyi; Balyejusa Kizito, ElizabethDrought tolerance is a complex trait whose inheritance had not been investigated in Solanum aethiopicum L. Shum group. This is partly because of perceived cross incompatibilities in the crop. This study relied on 24 successful crosses from an incomplete 9×4 North Carolina II mating design, evaluated under five watering conditions based on plant growth stage and watering level in order to determine the heritability of drought resistance and combining ability. Subsequent data analyses were based on restricted maximum likelihood. Overall, specific combining ability (SCA) effects were significant across and within watering environments for all study traits. The most highly heritable traits (in the narrow-sense) were identified as leaves per plant, chlorophyll content (CHL), leaf fresh yield and leaf dry yield while leaf area (LA), leaf relative water content (LRWC) and leaf mass area (LMA) were least heritable. However, the broad sense heritability (H2) was over 0.80 for seven of the traits, indicating that dominance gene action surpass additive gene effects for drought resistance in S. aethiopicum Shum. Further analysis showed that LA is suited for selection of best combiners under wellwatered and drought-stress (DS) treatments. The LRWC served best in separating the SCA effects of crosses under DS. The CHL produced clear separations of SCA effects under both DS and drought recovery while LMA served best under the latter.Item Identification of growth stage specific watering thresholds for drought screening in Solanum aethiopicum Shum(Scientific Reports, 2020) Nakanwagi, Mildred Julian; Sseremba, Godfrey; Kabod, Nahamya Pamela; Masanza, Michael; Balyejusa Kizito, ElizabethEffective phenotyping for drought resistance is a pre-requisite for identification of modest crop varieties for farmers. For neglected and underutilized crops such as Solanum aethiopicum Shum group, no drought screening protocol based on rigorous iterations has been documented. A split-plot nested treatment structure was arranged in an experiment to identify growth stage-specific watering thresholds for this crop. Three plant growth stages (main plot; seedling, vegetative and flowering), watering regime at plant growth stage (2 regimes; well-watered and drought stressed) and day since last watering at plant growth stage were evaluated for soil moisture content (SMC), leaf wilting score (LWS), number of green leaves per plant (LPP) and leaf blade width (LBW). Highly significant differences (p < 0.001) were found at the different plant growth stages, watering regime (WR) within plant growth stage, and day within WR and plant growth stage. Under drought stress treatment, SMC declined exponentially at each stage. The earliest leaf wilting, reduction in LPP and LBW were generally observed at flowering followed by vegetative and slowest at the seedling stage. For future effective drought phenotyping studies in S. aethiopicum Shum and related crops, we recommend setting minimum drought stress treatments below 18% SMC at which the LWS is ≥2 at the vegetative.Item Intraspecific crossability and compatibility within Solanum aethiopicum(Heliyon, 2021) Buteme, Ruth; Nakajiri, Mary; Kucel, Newton; Nahamya Kabod, Pamela; Sseremba, Godfrey; Balyejusa Kizito, ElizabethUnderstanding hybridization barriers is relevant for germplasm conservation and utilization. The prezygotic barriers to hybridization include floral morphological differences like pistil and stamen length, pollen characteristics and pollen-pistil interactions. This study sought to elucidate the reproductive biology of Solanum aethiopicum; its mating systems and compatibility barriers. Eight genotypes of Solanum aethiopicum were examined for differences in floral morphology, phenology and cross compatibility in a full diallel mating design, with assessment of fruit set, seed set and seed viability. In-vivo pollen tube growth was observed for failed crosses at 24, 48 and 72 h after pollination. All genotypes had heterostyly flowers, with predominantly small white petals. Incompatibility was observed in five out of 39 combinations. All selfed genotypes displayed compatibility implying the genotypes are self-compatible. Pollen–pistil incompatibility, which was exhibited in four out of the five failed cross combinations, occurred on the stigma, upper style and lower style, a phenomenon typical in Solanaceae. Solanum aethiopicum is self-compatible and majorly self-pollinating but has features that support cross-pollination.Item Morphological distinctiveness between Solanum aethiopicum Shum group and its progenitor(Journal of Plant Breeding and Crop Science, 2017) Sseremba, Godfrey; Tongoona, Pangirayi; Yaw Eleblu, John Savior; Yirenkyi Danquah, Eric; Kabod, Nahamya Pamela; Balyejusa Kizito, ElizabethUse of morphological markers offers an alternative in germplasm discrimination of research-neglected crop species. A collection of 25 accessions including five wild progenitors was evaluated in screen house to identify the morphological difference between Solanum aethiopicum Shum and Solanum anguivi. An Unweighted Pair Group Method with Arithmetic mean hierarchical clustering revealed presence of moderate structure with a cophenetic correlation coefficient of 0.73. Five distinct clusters were produced; the progenitor accessions for the S. aethiopicum Shum were grouped in their own cluster. The Richness, Shannon-Weaver and Simpson indices were also different among qualitative variable categories. A ‘prcomp’ function based Principal component analysis (PCA) in R on quantitative variables indicated that days to germination and emergence, cotyledonous leaf length, cotyledonous leaf width, shoot biomass, plant height, petiole length, days to first flowering opening, plant width, plant branching, and number of leaves per plant are the major drivers of variability in the study accessions. Further, results from canonical discriminant analysis to discern between the S. aethiopicum and its progenitor accession groups showed that the days to germination and emergence provide the best separation; with the former emerging earlier than the latter. The mean values for flowering time, leaves per plant, number of branches per plant and plant height were more favorable for the Shum than its wild progenitor accessions. The study revealed that morphological markers are useful in distinguishing between the S. aethiopicum Shum and its progenitor accessions.Item Performance of Solanum aethiopicum Shum group accessions under repetitive drought stress(Journal of Plant Breeding and Crop Science, 2017) Nakanwagi, Mildred Julian; Sseremba, Godfrey; Masanza, Michael; Balyejusa Kizito, ElizabethDrought is a serious climatic hazard to crop production, more especially when it occurs repeatedly. This created a need to identify repetitive drought tolerant varieties that recover following exposure to drought. Twenty accessions of Solanum aethiopicum Shum group were evaluated for their response to repeated drought exposure in a screen house at Uganda Christian University stressed and well-watered conditions in a split-plot arrangement. Data was collected on growth and yield parameters namely leaf area, plant canopy width, plant height, plant branching, fresh leaf weight, fresh shoot biomass, and harvest index. Exposure of plants to repetitive drought stress led to significant decrease in all evaluated growth parameters at p<0.001 except for plant branching. Similarly, yield parameters exhibited a highly significant difference among accessions and between water levels at p<0.001. Principal component analysis of growth rate traits showed that leaf area contributed to the highest variation for recovery from repetitive drought stress among accessions. The accessions that recovered best from drought stress include SAS108/2015, SAS163/P/2015, SAS183/G/2015, and SAS168/G/2015. For yield parameters, the accessions SAS137/2015, SAS148/2015, SAS108/P/2015, and SAS160/2015 had the highest dry shoot biomass. These findings indicate prospect for improvement of tolerance to repetitive drought stress in S. aethiopicum Shum group.Item Stability of Solanum aethiopicum Shum accessions under varied water deficit stress levels and identification of pertinent breeding traits for resistance to water shortage(Euphytica, 2018) Sseremba, Godfrey; Tongoona, Pangirayi; Yaw Eleblu, John Savior; Danquah, Eric Yirenkyi; Kaweesi, Tadeo; Baguma, Yona; Masanza, Michael; Balyejusa Kizito, ElizabethDrought is a major constraint to productivity of Solanum aethiopicum ‘Shum’ group due to loss in market and nutrient value of stressed plants. This study evaluated S. aethiopicum Shum group accessions to identify genotypes (G) that excel across moisture deficit stress levels (WLs). A split-plot arrangement composed of four WLs and twenty accessions of S. aethiopicum as main plot and subplot factors, respectively, was implemented in a screenhouse, and repeated for two experiments. In each experiment, there was a highly significant effect of at least two WLs on mean performance among at least two accessions for most of the traits at p\0.05. Further, very highly significant WL 9 G interactions were obtained for leaf relative water content (LRWC), leaves per plant (LPP) and plant height (PH), and nonsignificant for leaf blade length and leaf blade width. The order of priority as breeding traits for stability superiority across WLs was suggested as LRWC[PH[LPP. Consequently, based on LRWC, the most superiorly stable accessions were identified as accession 160 followed by accessions 145, 137, 108P and 184G while the least stable ones were identified as accessions 163G, 141, 163 and 108. The broad sense heritability (H2) for each of the three recommended traits for drought resistance breeding was above 0.9 thus supportive for a good response to selection. Drought stress negatively affected the performance of S. aethiopicum Shum group but the exhibited variation allowed for selection of superiorly stable genotypes.