Browsing by Author "Habineza, Jean Claude"

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    Effect of low temperature stress on field performance of highland sorghum (Sorghum bicolor (L.) Moench) at flowering stages
    (Journal of Plant Breeding and Crop Science, 2020) Rutayisire, Amandin; Mukayiranga, Alice; Habineza, Jean Claude; Avosa, Millicent; Edema, Richard; Lubadde, Geofrey
    Sorghum is a C4 grass native in the semi-arid environments of the African sub-Saharan and consequently chilling stress can affect the performance of the crop, especially at the reproductive stages. Moreover, a significant delay of flowering and maturity was observed when sorghum grows under low temperatures regions, and consequently farmers in highland areas of Uganda face yield penalties. Forty genotypes were evaluated in 2017B and 2018A seasons under non-stress (Kabanyolo) and cold stress (Kachwekano and Zombo) field conditions. Data were recorded on: Days to 50% flowering, days to physiological maturity, culm height, panicle length, panicle weight, kernel weight per panicle, and thousand grain weight. Mean comparison of most agronomic traits recorded indicated high significant differences for season-by-genotype, location-by-genotypes, and the three-way interaction (GxLxS). This indicates that cold stress significantly affects yield components. Significant positive correlation was obtained between days to 50% flowering, days to maturity, and culm height, which suggested that simultaneous improvement of these traits is possible. Some genotypes (IESV 91003LT, IESV 91105LT and IS 29376) were best ranked in normal environment but poorly performed in cold environments, which indicates lack of adaptation in highland. BM6, Cytanobe, IESV 91018, IESV 91609, IS 25563 showed generally good performance and stability in all locations. Therefore, these genotypes can be used as parental lines for further breeding process.
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    Identification of rice genotypes tolerant to submergence at seedling stage in Uganda
    (Journal of Plant Breeding and Crop Science, 2019) Bildadi Mlaki, Anna; Gibson, Paul; Edema, Richard; Habineza, Jean Claude; Mwanje, Gerald; Lamo, Jimmy; Nuwamanya, Ephraim
    Floods have destroyed over 2000 acres of rice in Uganda which affected yield and caused losses to farmers. This problem is more pronounced when fields are not well leveled, and the mode of irrigation is by surface flooding. Majority of lowland rice fields in East African region are of this nature and are thus prone to yield losses. There are no submergence tolerance varieties identified in Uganda, so far. To address this problem, breeding for submergence tolerance is the most ideal and promising strategy in rice. As a first step, genotypes tolerant to submergence need to be identified which is the objective of this study. 29 rice genotypes were morphological characterized in screen house and field conditions while 34 rice genotypes were molecularly characterized. Results suggested significant differences in the performance of genotypes both in the screen house and under field conditions in which varieties Swarna, IRRI SUPA 3 and KOMBOKA showed approximately 80% and above survival rate with Swarna variety ranking first. Molecular characterization of rice genotypes revealed that, out of 34 genotypes, 30 genotypes scored presence for Sub 1A-2 allele while, four genotypes were neither Sub1A-1 nor Sub 1A- 2 alleles. None of the tested genotypes were carrying Sub 1A-1 allele.