GENETIC DIVERSITY IN BAMBARA GROUNDNUT (Vigna subterranean) AS REVEALED BY MOLECULAR WEIGHTS OF THE SEEDS’ PROTEINS

Nine accessions of Bambara groundnut (Vigna subterranea (L.) Verdc.,syn. Voandzeia subterranea (L.) Thouars ex DC.) obtained from National Centre for Genetic Resources and Biotechnology (NACGRAB), Ibadan, Oyo state, were assessed for their genetic and phylogenetic relatedness through electrophoretic analysis of the seed proteins. 0.2g of the seeds were weighed and macerated with mortar and pestle in 0.2M phosphate buffer containing 0.133M of acid (NaH2PO4) and 0.067 of base (Na2HPO4) at pH 6.5. Protein characterization with standard marker revealed that the seeds of the nine accessions contained proteins (B.S.A, Oval Albumin, Pepsinogen, Trypsinogen and Lysozyme) with molecular weights ranging from 66kda and above, 45 – 65 kDa, 44 – 33 kda, 32-24 kDa and 23-14 kDa, respectively. The student T-test revealed that accessions B, C, E, F, H and I have molecular weights not significantly different from one another (P<0.05) while samples A, D and G showed significantly different values (P>0.05). All the accessions had at least two proteins and two major bands in common. The study revealed intra-specific similarities and genetic diversity in protein contents among the nine accessions of Bambara groundnut (Vigna subterraranea (L.) Verdc.syn

MORPHOLOGICAL CHARACTERIZATION OF COFFEE (Coffea arabica L.) LANDRACES AT SEEDLING STAGE COLLECTED FROM GUJI ZONES

The present study was aimed to determine genetic diversity of Coffea arabica landraces based on morphological characteristics at seedling stage in Guji zones. Three kebeles and twenty-five farmers’ coffee landraces were selected based on availability of Coffea arabica landraces from each district by the guidance of Developmental Agency in the kebele. Coffea arabica seeds were collected and planted at kercha nursery sub-site in plastic pots arranged on randomized block design. Seedling characteristics were collected from one year old randomly selected four coffee seedlings from each plot. The results showed that there were significant variations (p<0.05) between and within Coffea arabica landraces of the district. The seedling height of Coffea arabica collected from Didiba local was highest (11.25) followed by Sorile local (11.17) whereas Ebala local was the least. Coffea arabica from Diqisa local (5.25) was the highest for leaf height followed by Didiba local (5.13), Harobora (5.00) and Wacufora local (5.00). Similarly, Wacufora local (2.05) and Didiba local (2.53) were the highest in leaf width. The Coffea arabica landrace of Qaqali local (6.25) and Harobora local (5.75) were the highest in number of paired leaves. Correlation between the characteristics of coffee seedling showed that seedling height was high and significantly correlated with leaf width (0.62**), number of paired leaves (0.58**), node number (0.57**) and leaf area (0.64**). Similarly, leaf height was high and significantly correlated with leaf width (0.72**) and leaf area (0.77**). Generally, the increase of leaf height increases the leaf width and leaf area. Existence of morphological variation of Coffea arabica at seedling stage was used to determine Coffea arabica diversity in this study area. Therefore, Coffea arabica landraces having high seedling height, leaf height, number of paired leaves and leaf area should get attention during selection for plantation. Additionally, farmers, conservationists and other concerned bodies should take action to conserve and keep the gene pool of these coffees. As a result, it opens the door for biotechnologists to characterize coffee at molecular level and breeder scan take action on it to release superior coffee varieties.

INTER-SIMPLE SEQUENCE REPEAT ANALYSIS AND ALLELIC DIVERSITY AMONG GENOTYPES OF CULTIVATED Digitaria species

Acha (Digitaria exilis Kipps. and D. iburua Stapf.) are valuable indigenous food crops in West Africa, but despite several economic potentials of this crop, little or no attention is paid to its germplasm evaluation and improvement. In this study, we assessed genetic diversity and relationship among genotypes of cultivated acha in Nigeria using Inter-Simple Sequence Repeat (ISSR) markers for the first time. Genomic DNA were extracted from the genotypes and we performed fragment amplification by Polymerase Chain Reaction (PCR). A total of 95 loci consisting of 790 bands were amplified by 13 ISSR primers, out of which 53.37% were polymorphic. Loci amplification per primer ranged from 5-10, with an average of 7.30 loci per primer. Eight of the primers had above 50% polymorphism. Cluster analysis separated the genotypes into two major groups; a group consisting of two D. exilis genotypes and the other comprising a mixture of genotypes. The D. exilis in the latter group were distant members and was only similar at 0.72 similarity index. The polymorphism we obtained in the present study showed that the ISSR markers are effective for assessment of genetic diversity of the genotypes. Clustering of D. exilis and D. iburua together suggests a common progenitor but could have been separated by geographical isolation mechanism

GENETIC DIVERSITY OF RAPESEED (Brassica napus L.) GENOTYPES IN BANGLADESH

Genetic diversity in thirty eight traditional rapeseed genotypes was studied under favorable condition through Mahalanobis D2 statistic for yield and yield contributing characters. The genotypes were grouped into five clusters. The inter-cluster distances were higher than intracluster distances indicating wider genetic diversity among the clusters. The intra-cluster distances were lower in all the cases reflecting homogeneity of the genotypes within the clusters. Among the different cluster the genotypes of the cluster IV, III and I included were taller plant. The genotypes in the cluster III and IV had large size raceme. The genotypes in the cluster IV, III and V exhibited comparatively higher number of siliqua per raceme. Longer siliqua was noticed for the genotypes in the cluster III, IV and I. Higher number of seeds per siliqua noticed in clusters I, II and III. The genotypes of the cluster I and II produced bold size seed. The genotypes in the cluster V and I had high harvest index. The genotypes of the cluster III and I produced high seed yield per plant. Among the different cluster, the cluster III included the genotypes which had high yield, higher number of seeds per siliqua, longer siliqua, siliqua number per raceme and high plant height. Moreover these cluster displayed wide divergence with the genotypes of cluster V. The genotypes of the cluster V had the highest harvest index therefore selection of the parental material for crossing program for improvement of yield in rapeseed is suggested from these two clusters.

GENOTYPE-ENVIRONMENT INTERACTION IN YIELD OF HILL COTTON GENOTYPES

Stability analysis helps in understanding the adaptability of genotypes over different environmental conditions and the identification of adaptable genotypes. The experiment was conducted at the Chittagong Hill Tracts (CHT) areas of Bangladesh i.e. Bandarban, Rangamati and Khagrachari during May to September 2014 to study the genotype environment interaction effect on yield of some selected hill cotton genotypes. The experiment consisted of two factors: Factor A: Location (3 locations) - L1: Bandarban; L2: Rangamati and L3: Khagrachari; Factor B: Different cotton genotypes G1: HCG-4; G2: HCG-13, G3: HCG-15, G4: HCG-21, G5: HCG-26, G6: HCG-42, G7: HCG-51 and V8: HC-1 (Check). In case of location environment, the maximum boll per plant was recorded from Bandarban (19.13). The highest single boll weight was recorded from Bandarban (4.65 g). The highest seed cotton yield per hectare was recorded from Bandarban (1825 kg). The highest lint yield per hectare was recorded from Khagrachari (809 kg). For genotypes, maximum boll per plant (24.61), single boll weight (5.18 g), seed cotton yield per hectare (2170 kg) and lint yield per hectare (927 kg) was observed in HCG-13. In case of interaction of environments and genotypes, highest boll per plant (27.03), single ball weight (5.29 g), seed cotton yield per hectare (2170 kg), lint yield per hectare (981 kg) was observed in HCG-13 at Bandarban than the Rangamati and Khagrachari. Based on performance of eight genotypes HCG-13 followed by HCG-21 and HCG -42 was found to be highest yielder.Genotype HCG-13 was found highest yielder than the other genotypes and showed better performance at Bandarban than the Rangamati and Khagrachari.

VARIETAL PERFORMANCE AND CORRELATION OF OKRA POD YIELD AND YIELD COMPONENTS

Field irrigation experiments were conducted to assess the varietal performance and correlation of pod yield and yield attributes under irrigation at the Teaching and Research Farm, University of Maiduguri, Nigeria, during 2015 and 2016 dry seasons. The results revealed that the most outstanding for fresh pod yield per plant were okra cultivar Kwadag Y’ar gagure Salkade and, Kwadam in descending order with yield ranging from 580.38-622.67g, while the composite cultivar had the lowest value of pod yield of 428.62g over the two years. The highest mean values for number of pods per plant and number of primary branches per plant were observed for Salkade and Y’ar gagure, respectively. Highest fresh pod length and fresh pod diameter were also exhibited for Salkade and Kwadag, respectively. Genotypic coefficient of variation was higher than the phenotypic variation for all the yield contributing characters. Days to 50% flowering were positive and highly significance difference associated with plant height, number of pods per plant and fresh weight per pod. Path coefficient analysis showed that number of pods per plant exhibited positive and direct effects on pod yield across years. Indirect effect of other yield components through this character also contributed mainly towards pod yield. Therefore, plant height, days to 50% flowering, number of pods per plant, pod length, pod diameter, number of primary branches per plant and fresh weight per pod could be considered for selection and improvement for high pod yielding varieties in okra.

COMBINING ABILITY FOR FLOWERING AND YIELD TRAITS OF JATROPHA (Jatropha curcas L)

An experiment was conducted with 6 × 6 half diallel population to determine the combining ability for yield characters in Jatropha. Combining ability analysis revealed that both general and specific combining ability variances were significant for all the characters studied. GCA was observed to be higher in magnitude for majority of the characters except number of inflorescence per plant indicating that these characters were predominantly under additive genetic control. The non additive components of variance were also involved in the inheritance of number of inflorescence per plant. The parent P1 was the best general combiner for most of the traits including earliness and seed yield per plant and P5 was the poor general combiner for all the traits except hundred seed weight. Higher negative SCA effect was found in the cross combination P1×P3 for earliness and positive effect for seed yield per plant. Finally, it can be concluded that both additive and dominant genetic components are important for earliness and seed yield in Jatropha. The cross combination P1×P2, P1×P3, P2×P5 and P4×P6 is found promising for earliness and seed yield per plant. These combinations could be selected for the development of hybrid varieties in Jatropha.

GENOTYPE X ENVIRONMENT INTERACTION EFFECTS ON THE FIELD PERFORMANCE OF STEM AMARANTH (Amaranthus tricolor L.)

A research was carried out to find genotype x environment interaction effects on the field performance of 20 germplasm of Stem amaranth at Genetics Farm, Sher-e-Bangla Agricultural University, Dhaka during the period from November, 2013 to May 2014. The experiment was laid out in the Randomized Complete Block Design with three replications. Data were recorded on plant height (cm), no. of leaves per plant, individual leaf weight (gm), individual stem weight (gm), marketable stem weight (gm), yield (Kg/ha) at three environments. G-18 was the tallest with non significant S2di value (10.5) and G-9 was the shortest (2.22). G-20 produced most number of leaves with non significant S2di value (2.59) and G-01 was the least (11.56**). G-01 was the highest individual leaf weight with significant S2di value (46.08**) and G-15 was the least (2.84). G-01 was the highest individual stem weight with non significant S2di value (15.13) and G-09 was the least (48.09). The genotype G-01 produced the highest marketable stem weight with non significant S2di value (451.59) and G-09 was the least (39.77). G-01 was the highest yield producing with non significant S2di value (7821.539) and G-09 was the least (688.8164). Based on stable responses considering the higher yield character G-08 and G-18, for higher individual leaf weight G-07 and G-11, for higher individual stem weight G-18, for lesser dry weight of stem G-14 and G-18 genotypes could be selected for effective use in breeding program.

GENETIC DIVERSITY INAUS RICE LANDRACES OF BANGLADESH USING SSR MARKERS

Assessment of genetic diversity is essential for germplasm characterization, utilization and conservation. Genetic diversity of 31 Aus rice landraces of Bangladesh was assessed using 36 SSR (simple sequence repeats) markers. A total of 141 alleles were detectedand the number of alleles per locus ranged from two (RM1216, RM145, RM282, RM293, RM567and RM496) to 10 alleles (RM304), with an average of 3.92. The gene diversity varied from 0.06 (RM145) to 0.80 (RM304) with an average of 0.54 and the PIC values ranged from 0.06 (RM145) to 0.78 (RM304), with an average of 0.48.PIC value revealed that RM304 was the best marker for characterizing the studied Aus rice genotypes. The dendrogram from unweighted pair-group method with arithmetic average clustering of markers classified the genotypes into five major groups with a coefficient of 0.49. Two and three-dimensional graphical views of Principal Coordinate Analysis (PCA) revealed that the genotypes Hashikalmi, Chaina, Puitraaijang, Saithsail, Kuchmuch, Kalodhan, Ausdhan and Itcriewere found far away from the centroid of the cluster and can be selected as parents for further breeding programs.The results provided some useful implications for establishment of sovereignty of Bangladeshi rice gene pool. This information will provide maximum selection of diverse parents, background selection during backcross breeding programs and assist in broadening germplasm-based rice breeding programs in future.

BULB AND SEED YIELD POTENTIALS OF SUMMER ONION VARIETY DEVELOPED THROUGH INDUCED MUTATION

With a view to improve bulb and seed yield potentials of summer onion, seeds of BARI Piaz-2 were irradiated with 75 Gy, 100 Gy and 125 Gy doses of gamma rays from a 60Co source in 2006.Fifty four days old seedlings were transplanted on 20 January 2007.Thirteen, 12 and 9 M1 plants, respectively, from 75 Gy, 100 Gy and 125 Gy dosesproduced fertile seeds which were kept separately dose wise. In M2 generation, seedlings of 13 progenies from 75 Gy, 10 from 100 Gy and 7 from 125 Gy were transplanted on 15 December 2008 in plant- progeny- rows and 11, 7 and 6, respectively, were selected based on higher percentage of seed producing plants compare to parent BARI Piaz-2.In M3and M4 generations, 13 progenies, 6 each from 75 Gy and 100 Gy and the other from 125 Gy were further selected based on higher seed yield than the parent. Additionally, in M3 generation, observation trial with the above 13 mutant lines for bulb yield potential in Kharif-I seasonin 2011 revealed the mutant lines BP2/75/5 and BP2/100/2 had significantly higher fresh and dry bulb yield than BARI Piaz-2 and that of BP2/75/2 had not differed significantly. Shelf life expressed here as rate of weight loss on storage for 2.0 months under ambient condition exhibited all the 13 mutants had longer shelf life than the parent and the check variety. The mutant BP2/100/2 had the longest shelf life followed by BP2/125/1 and BP2/100/12 and BP2/75/13. Preliminary yield trial for seed yield potential in M4 generation in winter season of 2011-2012 showed all the 13 mutant lines could produce seed from seed in the same season but the parent BARI Piaz-2 failed. In advance yield trial for bulb yield potential in Kharif-II season of 2012, the mutants BP2/75/2, BP2/75/5 and BP2/100/2 produced significantly higher bulb yields atIshurdi and Magura than the check variety BARI Piaz-3.Unlike Kharif-I season the shelf life of the bulbs of mutants and the check variety did not differ significantly in Kharif-II although yield was almost double. Advance yield trial for seed yield potentialsin 2012-13 of five selected mutants showed all the mutant lines produced sufficient seeds from seed in the same season like preliminary yield trial. Seed production of the mutants ranged from 798-1193 kg/ha with the highest being in BP2/75/3 followed by BP2/75/2 while the parent BARI Piaz-2 produced the lowest seed yield of all.