Assessment of Soil Physico-Chemical Properties in Selected Natural Habitats of The Wild Rice (Oryza Longistaminata) and their Effects on the Species Morphological Characters

The aim of this study was to assess variation in some soil physical and chemical properties among four selected natural habitats of the wild rice species (Oryza longistaminata) in Tanzania, and their effects on the species morphological characters. Oryza longistaminata is a perennial wild rice species with agronomically important genes, including genes for tolerance to biotic and abiotic stresses that can be used in rice breeding. In Tanzania O. longistaminata grows sympatrically with the cultivated rice (Oryza sativa) in most rice cultivating areas. The selected natural habitats assessed were located in four districts, namely Bagamoyo, Kibaha, Kilombero and Mbarali. Soil samples were collected at the depth of 0 - 20 cm from the four districts and analysed in the laboratory for soil physico-chemical properties using standard protocols. The species morphological characters were assessed based on the morphological descriptors for wild and cultivated rice species developed by Bioversity International and International Rice Research Institute. One way ANOVA was used to determine the extent of variation in soil physico-chemical properties (parameters) among the four natural habitats of O. longistaminata. Canonical Correspondence Analysis (CCA) was used to determine the effects of assessed soil parameters on the morphological characters of O. longistaminata in the study areas. The study revealed variation in soil physico-chemical properties among the districts. Statistically there were significant differences among the habitats (districts) for most of soil physico-chemical properties investigated. In addition, the assessed soil physico-chemical properties were found to influence variation in morphological characters among O. longistaminata populations from different habitats

Diversity of Sorghum (Sorghum bicolor L. Moench) Germplasm from Tanzania

Sorghum (Sorghum bicolor L. Moench) is an important cereal crop cultivated in varied agro-ecological zones of Tanzania ranging from the southern highlands to coastal lowlands. Different cultivars and varieties of sorghum are needed for cultivation in such varied zones. Phenotypic properties of Tanzanian sorghums are not well-studied. Objective of this study was to phenotype some sorghum germplasm from Tanzania using morphological markers to establish their diversity for future use in breeding programs. Ninety-eight sorghum genotypes were evaluated at Bumala and Amagoro in Western Kenya during 2009 and 2010 seasons in a randomized complete block design. The International Plant Genetic Resource Centre descriptors of 1993 were used for data collection. Accession MCSR T29 was the earliest which took only 64 days while MCSR T80 was the latest taking 86 days to attain 50% flowering compared to the overall mean of 71 days. The MCSR T71 was the best yielder (114.6 g/ panicle) and MCSR T10 was the lowest (10.3 g/panicle) compared to overall mean of 92.4g/panicle. About 60% of the sorghums had brown and only 2.2% had black grains. MCSR T90 had bold grains with 1000 seed weight of 55.2g. Leaves per plant ranged from 7 in MCSR T69 to 17 in MCSR T25. Plant height ranged from 72.8 cm in MCSR T53 to 434.6 cm in MCSR T80. This study showed that, Tanzanian sorghums are diverse therefore could be used in future breeding programs for developing multipurpose and adapted cultivars. Keywords: Cultivars, Diversity, Phenotype, Varieties, SorghumSorghum (Sorghum bicolor L. Moench) is an important cereal crop cultivated in varied agro-ecological zones of Tanzania ranging from the southern highlands to coastal lowlands. Different cultivars and varieties of sorghum are needed for cultivation in such varied zones. Phenotypic properties of Tanzanian sorghums are not well-studied. Objective of this study was to phenotype some sorghum germplasm from Tanzania using morphological markers to establish their diversity for future use in breeding programs. Ninety-eight sorghum genotypes were evaluated at Bumala and Amagoro in Western Kenya during 2009 and 2010 seasons in a randomized complete block design. The International Plant Genetic Resource Centre descriptors of 1993 were used for data collection. Accession MCSR T29 was the earliest which took only 64 days while MCSR T80 was the latest taking 86 days to attain 50% flowering compared to the overall mean of 71 days. The MCSR T71 was the best yielder (114.6 g/ panicle) and MCSR T10 was the lowest (10.3 g/panicle) compared to overall mean of 92.4g/panicle. About 60% of the sorghums had brown and only 2.2% had black grains. MCSR T90 had bold grains with 1000 seed weight of 55.2g. Leaves per plant ranged from 7 in MCSR T69 to 17 in MCSR T25. Plant height ranged from 72.8 cm in MCSR T53 to 434.6 cm in MCSR T80. This study showed that, Tanzanian sorghums are diverse therefore could be used in future breeding programs for developing multipurpose and adapted cultivars. Keywords: Cultivars, Diversity, Phenotype, Varieties, Sorghu

Heterosis for yield and its components in sorghum (Sorghum bicolor L. Moench) hybrids in dry lands and sub-humid environments of East Africa

A study was conducted in 2011 and 2012 growing seasons to determine levels of heterosis and identify parents for use in sorghum hybrid production in East Africa. A total of 36 pairs of male sterile lines and 42 restorers were obtained from ICRISAT-Nairobi and used for generating 121 experimental hybrids in a line × tester mating design. The hybrids were then evaluated at Kiboko, Ukiriguru and Miwaleni locations in an alpha lattice design with three replications. Each genotype was grown in a 4 m long row at spacing of 60 cm ×50 cm. Phenotypic data were collected as per IPGRI, (1993) descriptors for sorghum on five randomly selected plants. There were significant differences among locations, crosses and male parents for all the characters studied. Female lines were highly significant for all traits except days to 50% flowering (DAF). Desired heterobeltiosis for DAF varied from -5.23 to -14% indicating of early maturing material that can escape terminal drought in rainfed agriculture, characteristic of East African cultivation system. Lowest (desired) heterobeltiosis for plant height was -53.61% with crosses ICSA15×Tegemeo and ATX623×KARI-MTAMA1most promising for this trait. Grain yield showed average heterosis and heterobeltiosis of up to 81.90% and 77.18% respectively both expressed in ICSA11×S35. The parents KARI MTAMA1, IESV91104DL, S35, BTX623, ICSB12 and ICSB11 produced hybrids that yielded high with medium height and maturity therefore could be included to develop hybrid sorghum for East Africa region

Combining ability of some sorghum lines for dry lands and sub-humid environments of East Africa

Sorghum (Sorghum bicolor L. Moench) is a major food crop grown in dry lands and sub-humid areas of East Africa. A study was conducted between 2010 to 2012 in dry lands (Miwaleni, Kiboko) and sub-humid (Ukiriguru) environments to identify parents for hybrid production. It involved 121 lines from ICRISAT and 121 hybrids developed from 36 male sterile lines and 42 restorer lines in a line × tester crossing. Experiments were planted in an alpha lattice design with three replications. Analysis revealed significant (P < 0.05) differences between parents and between crosses for yield and yield components, indicative of potentiality for exploitation. Line IESV23010 expressed best (-6.5) general combing ability (GCA) for days to 50% flowering (DAF). Highest general combiner for height was -55.4 expressed in ICSR24007 and for yield was 382.8 expressed in IESV92156DL. The crosses SDSA4×ICSR43 and SDSA4×ICSR59059 exhibited high and significant specific combining ability (SCA) for DAF. Lines IESB2 and ICSB44 were suited to sub-humid, whereas BTX623, ICSB15 and ICSB6 to dry lands environments. Testers IESV91104DL, IESV91131DL, ICSR93034 were well suited to dry lands whereas KARI-MTAMA1 and IESV23019 to sub-humid environments. The parents identified could be used to produce hybrids and varieties for the dry lands and sub-humid environments

Identification of SNP and SSR Markers in Finger Millet Using Next Generation Sequencing Technologies

Finger millet is an important cereal crop in eastern Africa and southern India with excellent grain storage quality and unique ability to thrive in extreme environmental conditions. Since negligible attention has been paid to improving this crop to date, the current study used Next Generation Sequencing (NGS) technologies to develop both Simple Sequence Repeat (SSR) and Single Nucleotide Polymorphism (SNP) markers. Genomic DNA from cultivated finger millet genotypes KNE755 and KNE796 was sequenced using both Roche 454 and Illumina technologies. Non-organelle sequencing reads were assembled into 207 Mbp representing approximately 13% of the finger millet genome. We identified 10,327 SSRs and 23,285 non-homeologous SNPs and tested 101 of each for polymorphism across a diverse set of wild and cultivated finger millet germplasm. For the 49 polymorphic SSRs, the mean polymorphism information content (PIC) was 0.42, ranging from 0.16 to 0.77. We also validated 92 SNP markers, 80 of which were polymorphic with a mean PIC of 0.29 across 30 wild and 59 cultivated accessions. Seventy-six of the 80 SNPs were polymorphic across 30 wild germplasm with a mean PIC of 0.30 while only 22 of the SNP markers showed polymorphism among the 59 cultivated accessions with an average PIC value of 0.15. Genetic diversity analysis using the polymorphic SNP markers revealed two major clusters; one of wild and another of cultivated accessions. Detailed STRUCTURE analysis confirmed this grouping pattern and further revealed 2 sub-populations within wild E. coracana subsp. africana. Both STRUCTURE and genetic diversity analysis assisted with the correct identification of the new germplasm collections. These polymorphic SSR and SNP markers are a significant addition to the existing 82 published SSRs, especially with regard to the previously reported low polymorphism levels in finger millet. Our results also reveal an unexploited finger millet genetic resource that can be included in the regional breeding programs in order to efficiently optimize productivity

Development of in vitro techniques for clonal multiplication and genetic fingerprinting of elite disease-free cashew (Anacardium occidentale L.)

Imperial Users onl

Characterisation of botanical starches as potential substitutes of agar in tissue culture media

Seven botanical starches; cassava, sweet potato, Irish potato, maize, rice, wheat and sorghum were characterized to determine physicochemical properties influencing gel formation for preparation of tissue culture media. Total starch, protein, fat, amylose content, swelling power and pH were determined using acid hydrolysis, enzymic and spectrophotmetric methods. Each type of starch was tested for ability to support in vitro plant growth and 0.8% agar (w/v) was used as standard. Nodal explants cultures were initiated in Murashige and Skoog medium supplemented with 3% sucrose and 0.5 mg/l benzylaminopurine (BAP). After 21 days, number of leaves and nodes, plant height and fresh weight were determined for each  treatment. Significant (0.05) differences were observed between starch types in total starch, protein content and fats. Cassava had the highest starch content (81.5%) and irish potato had the lowest (29.3%). Highest protein content (12%) was observed in maize starch and the lowest (3.4%) in cassava. Fat content was highest (6.2%) in wheat and lowest in cassava (0.2%). Starch extract from rice had the highest amylose content (31.12%) while the cassava starch extracts had the lowest (20.75%). The starch extracted from wheat had the highest swelling power (105.1%) while irish potato starch had the lowest (52.1%). Sorghum starch had the lowest pH of 4.57 while the highest (6.92) was recorded in Irish potato starch. The growth of shoots in vitro on agar gelled media outperformed those of starch gelled media except for the number of leaves per shoot which cassava starch media recorded significantly the highest response (P = 0.05). Of all the starch gelled media, the best growth response was observed with cassava. Good performance was observed in starches with high starch content, low amylose content and high swelling powers. Key words: Starch, agar, gelling agent, in vitro plant growth

Characterisation of botanical starches as potential substitutes of agar in tissue culture media

African Journal of Biotechnology, 2015; 14 (8): 702-713Seven botanical starches; cassava, sweet potato, Irish potato, maize, rice, wheat and sorghum were characterized to determine physicochemical properties influencing gel formation for preparation of tissue culture media. Total starch, protein, fat, amylose content, swelling power and pH were determined using acid hydrolysis, enzymic and spectrophotmetric methods. Each type of starch was tested for ability to support in vitro plant growth and 0.8% agar (w/v) was used as standard. Nodal explants cultures were initiated in Murashige and Skoog medium supplemented with 3% sucrose and 0.5 mg/l benzylaminopurine (BAP). After 21 days, number of leaves and nodes, plant height and fresh weight were determined for each treatment. Significant (0.05) differences were observed between starch types in total starch, protein content and fats. Cassava had the highest starch content (81.5%) and irish potato had the lowest (29.3%). Highest protein content (12%) was observed in maize starch and the lowest (3.4%) in cassava. Fat content was highest (6.2%) in wheat and lowest in cassava (0.2%). Starch extract from rice had the highest amylose content (31.12%) while the cassava starch extracts had the lowest (20.75%). The starch extracted from wheat had the highest swelling power (105.1%) while irish potato starch had the lowest (52.1%). Sorghum starch had the lowest pH of 4.57 while the highest (6.92) was recorded in Irish potato starch. The growth of shoots in vitro on agar gelled media outperformed those of starch gelled media except for the number of leaves per shoot which cassava starch media recorded significantly the highest response (P = 0.05). Of all the starch gelled media, the best growth response was observed with cassava. Good performance was observed in starches with high starch content, low amylose content and high swelling powers

Characterisation of botanical starches as potential substitutes of agar in tissue culture media

African Journal of Biotechnology, 2015; 14 (8): 702-713Seven botanical starches; cassava, sweet potato, Irish potato, maize, rice, wheat and sorghum were characterized to determine physicochemical properties influencing gel formation for preparation of tissue culture media. Total starch, protein, fat, amylose content, swelling power and pH were determined using acid hydrolysis, enzymic and spectrophotmetric methods. Each type of starch was tested for ability to support in vitro plant growth and 0.8% agar (w/v) was used as standard. Nodal explants cultures were initiated in Murashige and Skoog medium supplemented with 3% sucrose and 0.5 mg/l benzylaminopurine (BAP). After 21 days, number of leaves and nodes, plant height and fresh weight were determined for each treatment. Significant (0.05) differences were observed between starch types in total starch, protein content and fats. Cassava had the highest starch content (81.5%) and irish potato had the lowest (29.3%). Highest protein content (12%) was observed in maize starch and the lowest (3.4%) in cassava. Fat content was highest (6.2%) in wheat and lowest in cassava (0.2%). Starch extract from rice had the highest amylose content (31.12%) while the cassava starch extracts had the lowest (20.75%). The starch extracted from wheat had the highest swelling power (105.1%) while irish potato starch had the lowest (52.1%). Sorghum starch had the lowest pH of 4.57 while the highest (6.92) was recorded in Irish potato starch. The growth of shoots in vitro on agar gelled media outperformed those of starch gelled media except for the number of leaves per shoot which cassava starch media recorded significantly the highest response (P = 0.05). Of all the starch gelled media, the best growth response was observed with cassava. Good performance was observed in starches with high starch content, low amylose content and high swelling powers

Identification of SNP and SSR markers in finger millet using Next generation sequencing technologies

Finger millet is an important cereal crop in eastern Africa and southern India with excellent grain storage quality and unique ability to thrive in extreme environmental conditions. Since negligible attention has been paid to improving this crop to date, the current study used Next Generation Sequencing (NGS) technologies to develop both Simple Sequence Repeat (SSR) and Single Nucleotide Polymorphism (SNP) markers. Genomic DNA from cultivated finger millet genotypes KNE755 and KNE796 was sequenced using both Roche 454 and Illumina technologies. Non-organelle sequencing reads were assembled into 207 Mbp representing approximately 13% of the finger millet genome. We identified 10,327 SSRs and 23,285 non-homeologous SNPs and tested 101 of each for polymorphism across a diverse set of wild and cultivated finger millet germplasm. For the 49 polymorphic SSRs, the mean polymorphism information content (PIC) was 0.42, ranging from 0.16 to 0.77. We also validated 92 SNP markers, 80 of which were polymorphic with a mean PIC of 0.29 across 30 wild and 59 cultivated accessions. Seventy-six of the 80 SNPs were polymorphic across 30 wild germplasm with a mean PIC of 0.30 while only 22 of the SNP markers showed polymorphism among the 59 cultivated accessions with an average PIC value of 0.15. Genetic diversity analysis using the polymorphic SNP markers revealed two major clusters; one of wild and another of cultivated accessions. Detailed STRUCTURE analysis confirmed this grouping pattern and further revealed 2 sub-populations within wild E. coracana subsp. africana. Both STRUCTURE and genetic diversity analysis assisted with the correct identification of the new germplasm collections. These polymorphic SSR and SNP markers are a significant addition to the existing 82 published SSRs, especially with regard to the previously reported low polymorphism levels in finger millet. Our results also reveal an unexploited finger millet genetic resource that can be included in the regional breeding programs in order to efficiently optimize productivity