Collection characterization and evaluation of selected genetics resourses from land races of oryza sativa linn.

Umunnakwe, Elizabeth Chiamaka (2015)

xiv,60

Thesis

Seeds of some landraces of rice, Oryza sativaLinn., collected from farmers in different agro-zones and locations in Nigeria were raised, selected, characterized and evaluated. The pattern of protein distribution in the seeds of the selected landraces was also determined. Thiswas with a view to documenting the agro-botanical characteristics of the selected landraces of rice; determining the potentials of the characters documented for utilization in rice improvement programme; and investigating the pattern of protein distribution in the seeds of the selected landraces. The rice seeds were planted in a nursery at the reforestation nursery site, the Department of Botany, ObafemiAwolowo University, Ile-Ife, in 2013 and transplanted to a plot after four weeks for field evaluation. A spacing of 30 x 30 cm within rows was used and 60 cm distance between collections from different locations. Selections were made based on tillering habit, panicle density and days to maturity. The selections were planted out in lines with the same spacing and at the same plot in 2014. Data were collected on morphological parameters such as culm height, tiller number,culm strength, length and breadth of flag leaf and leaf below the flag leaf, ligule length; and panicle characters according to the DescriptorsforRice, Oryza sativa L. Pattern of protein distribution of the rice grainswere determined according to standard procedure. Data collected wereanalysed using descriptive statistics; cluster analysis for similarity or difference among the selections and correlation analysis for relationship among characters of the selections. The results revealed that among the selections, IFWPr++Fs-115 had the highest culm height while AWGUIIPr++Fs-78had the shortest; AWGUIII-113 had the highest tiller number, IFWPr++Fs-115 and IJsllwFs-02 had the longest panicle and rachis lengths, respectively. IFWPr++Fs-258 and IFWPr++Fs-55were observed to have the highest number of primary and secondary branches while highest number of tertiary branches was observed in AWGUIIFs-04. IFWPr++Fs-258 had the highest number of spikelets per panicle. The dendrogram of the cluster analysis carried out showed that selections from Ijesa-Isu and Ikole populations are closely related; AGWU populations are probably from the same stock while the Ifewara population had a wide genetic variability which made it cluster with the AGWU populations. Results of the correlation analysis showed that characters such as culm height, tiller number, flag leaf, number of primary and secondary branches, and ligule length could be considered as selection criteria in breeding programme. The transverse section of the seeds of the selections showed rows and clusters of protein bodies in the aleurone layer, some showed bands of protein bodies in the aleurone layer with some protein bodies extending into the endosperm. The study concluded that there is a wide genetic variability across the various collections of the landraces of rice and this could be of great potentials for rice improvement

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