Fingerprinting and Relating Juvenile Characters of Rice to Yield and Yield Components in Kiambu and Kirinyaga Counties
Henga, Sylvia A.
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Rice is increasing as an important food and cash crop in Kenya and is third to maize and wheat in terms of consumption. Consumption has continually outstripped production resulting in massive importation. The main problem affecting productivity involves lack of proper information on best storage time, use of poor quality seed, varietal admixtures which has contributed to low yields. There is need to characterize genotypes. Microsatellit are useful in various plant genetic studies and plant characrerization. Accelerated aging is considered an excellent option as a vigor test due to shortest time of acquisition and efficient results. In the proposed study, seed quality experiments including germination, dormancy, purity, were carried out in the laboratory using eight rice varieties in a Completely Randomized Design. Accelerated ageing tests at 0,24,48 and 72hrs(45oC and 98%RH) were carried out JKUAT post-harvest laboratory using eight rice varieties‟ in four replications of100 seeds each. Data was collected on dates to plumule and radical emergence and height. Five varieties were used to produce seeds which were stored for 1,2,3,4,5 and 6 months respectively. The seedlings were transplanted into fields in a Randomized Complete Block Design using 5*6 factorial arrangement. The study also determined the relationship between juvenile characters and adult characters of rice in Kiambu and Kirinyaga counties. All the data were analyzed using GENSTAT statistical package. ANOVA and LSD at 5% significant level. Seed quality results showed that There was significant variation in both coleorrhiza and coleoptile formation among rice varieties (p<0.001), treatments (p<0.001) and interaction between rice varieties and treatment ((p<0.001). The difference between all treatments was significant with 72 hours treatment having the highest number of days to coleorhiza and coleoptile formation. Results showed that the effect of genotype on coleorhiza and colleoptille formation was significant (p<0.001). Genotype B317 had the earliest colleoptile formation 8.75days, coleorhiza formation (9.81), B317 also had the highest germination percentages at 7(33.69), 14 (52.44) and at 21 days after sowing (56.62). Mzungu had the latest number of days to coleorhizae (12.44), coleoptiles (11.18) and lowest germination percentages at 14(27.52) and 21days (31.31). The genotype had significant effect on germination index, seed length and seedling vigor index. In Mwea, there was a significant effect of storage time on germination, with 4 months giving the highest seedling vigor index (673.6), height at 1 month after transplanting (73.3cm), height at maturity (72.3cm) and 3 months giving the highest days to flowering(58.87) .The interaction between storage time and genotype on was significant, with genotype B217 stored for 3 months leading in height at one month after transplanting (87.7), height at maturity(91.8cm) .in Kiambu.The interaction between storage time and genotype was significant with 5months of storage having the highest seedling vigor index (759.5), 1000grain weight (69) and yield (15.5kg/ha). Analysis of molecular variance results indicated that the five polymorphic markers used in this study showed a total of 11 alleles across the loci of the 18 rice genotypes studied. Juvenile characters such as seedling vigor and height at transplanting had a positive and significant correlation to 1000grain weight.Genotypes TXD and B217 were identified by the 5 markers. TXD (Saro 5) was the best fit for fingerprinting as it was identified by only 1 marker. These results could be used in preparing rice seed certification procedures, in gene bank management and other seed storage ventures