VEGETATIVE IMPROVEMENT OF THREE NIGERIAN SESAME VARIETIES AFTER FNI TREATMENT

The effects of Fast Neutron Irradiation (FNI) from an Americium Beryllium source with a flux of 1.5 × 104 n cm-2 s-1 on select vegetative parameters of three Nigerian sesame (Sesamum indicum L.) varieties were investigated. Seeds of Kenana-4 , Ex-Sudan and E-8 were irradiated with 4, 8, 12 and 16 µSv doses of FNI before they were grown to maturity, alongside their respective controls (0 µSv dose of FNI). The vegetative parameters investigated included percentage survival, petiole length, number of leaves per plant, leaf surface area and plant height. There were significant differences (p<0.05) between the different doses of FNI for all three varieties. Correlations between irradiation doses and morphological parameters were generally highest in E-8, followed by Kenana-4, while Ex-Sudan showed the weakest correlations, suggesting that E-8 was the most sensitive to FNI. Thus, FNI can induce genetic variability in sesame and may be important for sesame breeders who seek to expand the genetic base of their breeding material

ESTIMATION OF HERITABILITY AND PREDICTED GENOTYPE MEAN FOR SEED YIELD OF CASTOR (RICINUS COMMUNIS L.) USING BEST LINEAR UNBIASED PREDICTION (BLUP)

Eighty six castor genotypes were evaluated to estimate heritability and predicted genotype mean for seed yield and its component traits. The genotypes were planted at three locations using incomplete block experimental design with three replications. The results revealed significant effects of genotypes for most of the traits evaluated. Significant interactions of genotypes by locations were observed for six traits including 100 seed weight and seed yield. Genotypic coefficient of variation and phenotypic coefficient of variation were high for number of branches per plant and 100 seed weight. Heritability for the studied traits ranged from 0.21 to 0.92. High genetic advance as percentage of mean coupled with high heritability were observed for most of the traits. Thirty six out of eighty six genotypes evaluated presented predicted genotypic seed yield mean above the general mean. These results revealed moderate to high possibility for improvement of five out of ten traits evaluated

Spectrum and Frequency of Mutations Induced by Gamma Radiations in Three Varieties of Nigerian Sesame (Sesamum indicum L.)

Insufficient genetic variability is one of the major problems of plant breeding programmes, especially in sesame. Gamma radiation has been reported to be very effective in creating genetic variability in plants. Three varieties of Nigerian sesame were assessed for spectrum and frequency of mutation induced by Gamma radiations in M1 and M2 generations. The varieties (NCRIBEN-04E, NCRIBEN-01M and NCRIBEN-03L) were treated with four different doses of gamma rays (250, 350, 450 and 550 Gy). The treated and untreated seeds (control) were sown in planting bags (under field condition) to raise M1 plants. Four treatments: V1D5, V2D3, V3D2 and V3D4 (from M1 plants) were selected and bulked to obtain M2 populations. The results of M1 revealed four mutant fruit traits: multicarpellate capsule, multiple capsule per leaf axil, indehiscent capsule and terminal capsules. The highest frequencies of the traits in M1 generation were 2.50×10-2, 9.17×10-2, 1.67×10-2and3.33×10-2 respectively. The highest branching (7) was from NCRIBEN-01M, while the least (2) was from NCRIBEN-04E. The M2 plants were grouped into eight M2 lines. The dose range (250-550 Gy) was proved to be effective in inducing viable mutations in sesame

PRELIMINARY STUDIES ON EFFECTS OF GAMMA RAY ON SEED RETENTION INDICES OF THREE NIGERIAN SESAME (SESAMUM INDICUM L.) VARIETIES

In an attempt to improve sesame for reduction of seed loss due to shattering of capsule at harvest, the seeds of three varieties of sesame (NCRIBEN-04E, NCRIBEN-01M and NCRIBEN-03L) were treated with five different doses (0, 250, 350, 450 and 550 Gy) of gamma irradiation; 0 Gy being the control. All the treatments including the controls, were grown and monitored till maturity. The seed retention power of the treatments were assessed. From the results, the treatment due to 550 Gy had highest score (6) for both NCRIBEN-04E and NCRIBEN-01M and was categorized as non-shattering (NSH) type. All other treatments were categorized as shattering (SHA) type. Similarly all the treatments from NCRIBEN-03L were categorized as SHA with treatment due to 250 Gy having highest score (5). The three varieties showed positive correlations between the seed/capsule in upright (U) and seed/capsule in inverted (I) position but NCRIBEN-01M was not significant (r = 0.650). The NCRIBEN-04E showed negative correlation between U and length of suture (L) and I and L (r = -0.570 and -0.358 respectively). This result has shown that the dose 550 Gy seems to be promising in generating mutants with high resistance to capsule shattering in sesame. There is need to advance these mutants to M2 and M3 generations to ascertain this seed retention capacity