African Journal of Plant Breeding

African Journal of Plant Breeding ISSN: 2375-074X Vol. 9 (8), pp. 001-013, August, 2022. © International Scholars Journals

Full Length Research Paper

Combining ability analysis for drought tolerance among single-cross tropical maize (Zea mays L.) hybrids in semi-arid Kenya

Dorothy Wanjala Wachenje¹, Pascal P. Okwiri Ojwang¹ and Murenga Mwimali²

¹Department of Crops, Horticulture and Soils, Egerton University, P.O. Box 536-20115, Njoro, Kenya.

²Kenya Agricultural and Livestock Research Organization, P.O. Box 57811-0200, Nairobi, Kenya

Accepted 26 July, 2022

Abstract

Drought stress is a major challenge in maize (Zea mays L.) production negatively impacting on production in semi-arid areas of eastern Africa. Breeding hybrid cultivars for semi-arid areas is essential to reduce yield losses experienced under rain-fed maize production. The objective of this study was to estimate combining ability for drought tolerance among single-cross maize hybrids in semi-arid environments. Eleven parents with known drought resistance were crossed in a half diallel mating design to generate 55 crosses, the Griffing’s diallel method IV, model II was used in analysis. The F1s, alongside two local checks, were evaluated in α-lattice design with two replications during 2020/2021 cropping season. Combined analysis of variance over environments revealed significant (p<0.05) main effects for genotypes, locations, and genotype-by-location interactions in most traits studied. Significant (p< 0.05) general combining ability (GCA) and specific combining ability (SCA) for grain yield, ear height and plant height demonstrated the role of additive and non-additive genetic variance in inheritance of these traits. Hybrids KAT-DT-EE-07×KAT-DT-EE-14 and KAT-DT-EE-07×KAT-DT-EE-04 had superior grain yield of 6.18 t ha^-1 and 6.16 t ha^-1, respectively. KAT-DT-M-31×KAT-DT-EE-07 showed significant SCA  for grain yield which demonstrated the potential of obtaining drought tolerant hybrids for possible  deployment to farmers.

Key words: drought stress, general combining ability, heritability, hybrid cultivars, specific combining ability.

African Journal of Plant Breeding ISSN: 2375-074X Vol. 9 (8), pp. 001-009, August, 2022. © International Scholars Journals

Full Length Research Paper

Morphological and agronomical characterization of Sweet potato [Ipomoea batatas (L.) Lam.] germplasm collection from Tanzania

Fred Tairo*, Emmarold Mneney, and Alois Kullaya

Mikocheni Agricultural Research Institute, P. O. Box 6226, Dar-Es-Salaam, Tanzania.

Accepted 20 April, 2022

Abstract

One hundred and thirty six sweet potato (Ipomoea batatas) landraces collected from three different agro-ecological zones of Tanzania [Lake Victoria basin (LZ), Eastern (EZ) and Southern Highlands Zones (SHZ)] were characterized morphologically and agronomically using International Potato Centre (CIP) descriptors in two seasons. The cluster analysis revealed existence of two major groups, 1 and 2 with low genetic variability of 0.52. Number of roots, weight of roots, fresh weight/plant and dry matter content differed significantly among and within agro- ecological zones. Landraces Lubisi from southern highlands zone had the highest number of roots (12 per plant) and Shinamugi from Eastern zone had highest dry matter content of 39.4%. Overall, landraces from Lake Zone recorded highest average root weight of 8,977.7 kg ha-¹ followed by Southern highlands (7,561.2 kg ha^-1) and Eastern zone (4,333.0 kg ha^-1). Principal coordinate analysis (PCA) indicated variances accumulated by the first five components of the six major morphological characters was 52.5% and produced similar groups corresponding to those of cluster analysis. Our data indicate low genetic variation despite significant variations shown by agronomical traits. Many landraces recorded in different names from three different agro ecological zones showed close resemblance and grouped into two major groups suggesting presence of dupl-icates or mislabelling.

Keywords: Morphological traits, agronomical traits, diversity, germplasm characterization, Ipomoea batatas, sweet potato

African Journal of Plant Breeding ISSN: 2375-074X Vol. 9 (5), pp. 001-006, May, 2022. © International Scholars Journals

Full Length Research Paper

Bioindicators in sustainable management of tropical forests in India

P. C. Kotwal, L. S. Kandari^* and D. Dugaya 

Indian Institute of Forest Management, P. Box # 357, Nehru Nagar, 462003, Bhopal, Madhya Pradesh, (India).

Accepted 16 March, 2022

Abstract

Nature follows its own pattern to regulate the dynamic ecosystem. If the process is closely monitored it provides indication for the cause and effect of the changes occurring owing to natural factors and anthropogenic activities. The bioindicators are potentially useful tool for the scientists, researchers and foresters to assess the sustainable forest management (SFM) in countries like India, which is rich in biodiversity at ecosystem, species and genetic levels. Although the concept of bioindicators is well known to indicate the change in the forest ecosystems but its application in monitoring the health of forest ecosystems and its documentation is limited in India. Despite of heavy anthropogenic and developmental pressures (2.1% of the land mass, about 1% forest area, 16% human population and 18% livestock population of the world); India is committed to SFM. In this study, an attempt has been made to classify and identify the range of bioindicators (plants and animals both) in reference to SFM in two Forest Management Units (FMUs) in Central India.

Key words: Bioindicators, Biodiversity, Indicators, Sustainable forest Management, Criteria and Indicator, Forest Management Unit.

African Journal of Plant Breeding ISSN: 2375-074X Vol. 9 (4), pp. 001-006, April, 2022. © International Scholars Journals

African Journal of Plant Breeding ISSN: 2375-074X Vol. 9 (2), pp. 001-004, February, 2022. © International Scholars Journals

Full Length Research Paper

Regeneration of plants from rice caryopsis derived callus culture of Nigerian local cv. Suakoko 8 and a NERICA cv. FARO 55

Abolade S. Afolabi^1*, O. Oyebanji¹, O. Odusanya¹, M. E. Abo², M. Misra³ and G. H. Ogbadu¹ 

¹Biotechnology Advanced Laboratory, Sheda Science and Technology Complex, PMB 186, Garki, Abuja FCT, Nigeria.

²National Cereal Research Institute, Badegi, Bida, Niger State, Nigeria.

³M. Misra, Institute of Frontier Sciences and Biotechnology, Baramunda, Bhubaneswar-751003, India.

Accepted 14 October, 2021

Abstract

The regeneration protocol for rice plants from callus culture obtained from dehusked and sterilized whole rice seeds (caryopses) of a popular Nigerian local cultivar Suakoko 8, and a NERICA cultivar FARO 55 is described. Utilizing a modified Nippon Barre medium (NBm) consisting of: Macro N6, Micro B5, Fe-EDTA, B5 vitamin and 30 mg/l of locally produced St Louis® sugar (to save cost) supplemented with casein hydrolysate and proline, and with cytokinin and auxin hormones (ratio 1:10), profuse and friable calli were obtained at 25^oC in the darkness. The friable calli produced were transferred to fresh medium once every week for three weeks before transferring them to pre-regeneration medium containing ABA and NAA (replacing 2-4,D in the callus induction medium), and incubated for 9 days in the darkness at 25^oC. Finally the creamy calli were transferred into regeneration medium containing high cytokinin (3 mg l^–1 BAP) with incubation at 28^oC and 12 h – photoperiod. Regeneration of plantlets was obtained between two to four weeks of transfer on the regeneration medium. The regeneration frequency (efficiency) of 53 and 42% were obtained for Suakoko 8 and FARO 55. Regenerated plants also produced viable seeds and hence fertile plants.

Key words: Embryogenic calli, regeneration, Suakoko 8, FARO 55, new rice for Africa (NERICA), Oryza sativa, Oryza glaberrima

African Journal of Plant Breeding ISSN: 2375-074X Vol. 8 (9), pp. 001-008, October, 2021. © International Scholars Journals

Full Length Research Paper

Genetic characterization of flood tolerance in a segregating population of tomato using RAPD Markers

Vincent Ishola Esan^1,2 and Tatsiana Dasenka¹

¹Department of Horticulture and Landscape Architecture, Purdue University, 625 Agriculture Mall Drive, West Lafayette, IN 47907, United States.

²Environmental Management and Crop Production, Bowen University, Iwo, Nigeria.

Accepted 02 September, 2021

Abstract 

Due to the heterogeneity of soils and the effects of changes in climate, the roots, although well anchored in the soil, are subject to environmental conditions. Flooding causes the absence of oxygen which negatively affects crop production and yields, resulting in decline of yields up to 10% or 40% decreasing in food supply for a rising human population. Therefore, the aim of the present work is to identify genes related to chlorophyll content, yield and yield component in tomato subjected to flooding, and to determine markers associated with these traits. The experiment was carried out in the greenhouse and a total of 122 F₂ plants obtained by crossing flood-tolerant cultivar (CLN2498E) with flood-sensible wild species (LA1579) and 4 plants for each parental line. Bulked segregant analysis was used as a method for identifying markers linked to genes responsible for flooding tolerance in tomato. Two pooled DNA sampled were obtained from F2 populations. Three RAPD markers were found tightly linked to the genes responsible for flood tolerance in tomato.

Keywords: Flooding, BSA, RAPD primers, genes responsible for flood tolerance in tomato.