African Journal of Crop Science

African Journal of Crop Science ISSN: 2375-1231 Vol. 13 (4), pp. 001-005, April, 2025. Available online at www.internationalscholarsjournals.org © International Scholars Journals

Full Length Research Paper

RAPD-Based Genetic Diversity in Cotton: Evaluating the Efficiency of Molecular Markers for Breeding Purposes

L. Chaudhary1*, A. Sindhu, M. Kumar, R. Kumar2 and M. Saini3

1Department of Biotechnology Engineering, Ambala College of Engineering and Applied Research, Mithapur, Ambala
Cantt., Haryana, India- 133 101.
2Department of Botany and Plant Physiology, CCS Haryana Agricultural University, Hisar-125 004, India.

3Department of Plant, Soil and Agricultural System, Southern Illinois University, Carbondale-62901, USA.

Accepted 5 January, 2025

Total genomic DNA from 15 cotton varieties were analysed to evaluate genetic diversity among them through random amplified polymorphic DNA (RAPD) analysis, with 30 random decamer primers using the polymerase chain reaction (PCR). A total of 370 bands were observed, with 12.3 bands per primer, of which 91.6% were polymorphic. OPM-16 produced the maximum number of fragments while the minimum number of fragments was produced with the primer OPM-18. Cluster analysis by the unweighted paired group method of arithmetic means (UPGMA) showed that 15 varieties can be placed in five groups with a similarity ranging from 0.48 - 0.86. Maximum similarity was observed between H-777, H-974 and H-1098 (0.86). Interestingly, these varieties have been developed at one breeding center. The analysis revealed that the intervarietal genetic relationship of several varieties is related to their center of origin. Most of the varieties have a narrow genetic base. These results were well in accordance with previous reported results. The RAPD analysis indicates that it may be a more efficient marker than morphological marker, isozyme and restriction fragment length polymorphism (RFLP) technology. The results obtained can be used in selecting divergent parents for breeding and mapping purposes.

Key words: Cluster, cotton varieties, diversity, RAPD, genetic similarities.
 

African Journal of Crop Science ISSN: 2375-1231 Vol. 13 (4), pp. 001-008, April, 2025. Available online at www.internationalscholarsjournals.org © International Scholars Journals

Full Length Research Paper

Evaluation of Pretreatment Efficiency in Durum Wheat Androgenesis: A Study on Green Haploid Production in Tunisian Cultivars

O. Slama Ayed1*, J. De Buyser2, E. Picard2, Y. Trifa1 and H. Slim Amara1

1Laboratoire d’amélioration génétique des Céréales, Institut National Agronomique de Tunisie, 43 Avenue Charles
Nicolle 1082 -Tunis- Mahrajène Tunisia.
2Laboratoire de Morphogenèse Végétale Expérimentale Haploïde, Bat. 360, Université Paris sud XI Orsay- 91405

Cedex, France.

Accepted 11 December, 2024

The production of double haploids through androgenesis is used by breeders to produce homozygous lines in a single generation. Androgenesis can be achieved by isolated microspore culture, which, however, allows the production of green haploids with a very low efficiency. In order to improve the overall green haploid regeneration in durum wheat, we compare the efficiency of eight different pretreatments. These pretreatments were: cold pre-treatment for 5 weeks, 0.3M mannitol for 12 days at 4°C; 0.3M mannitol for 7 days at 4°C; 0.7M mannitol for 5 days at 4°C; PEG4000 1.5% for 5 days at 4°C; PEG4000 1% for 15 days at 4°C; PEG4000 1% for 10 days at 4°C and control without pretreatment. The cold treatment for 5 weeks (4°C) is the most efficient and was used to test the androgenetic ability by microspore culture method of three Tunisian durum wheat cultivars (Razzek, Khiar and Azizi).This pre-treatment improves significantly the embryogenesis induction and green plants regeneration with green/albina ratio 2 for the cultivar “Khiar”. The PEG4000 1% for 10 days seems promising pre-treatment and this is important to perform new experiments to advance their response.

Key words: Isolated microspore culture, double haploid, durum wheat, pre-treatment.
 

African Journal of Crop Science ISSN: 2375-1231 Vol. 13 (4), pp. 001-006, April, 2025. Available online at www.internationalscholarsjournals.org © International Scholars Journals

Full Length Research Paper

Genetic Analysis of Yield Components in Durum Wheat: Gene Effects and Epistasis

Bnejdi Fethi and El Gazzah Mohamed

Laboratoire de Génétique et Biométrie, Département de Biologie, Faculté des Sciences de Tunis, Université Tunis, El Manar, Tunis 2092, Tunisia.

Accepted 2 January, 2025

Genetic control of the number of heads per plant, spikelets per spike and grains per spike was studied in two durum wheat (Triticum durum Desf.) crosses, Inrat 69/Cocorit71 and Karim/Ben Bechir, respectively. Separate analyses of gene effects were done using means of four generations (parents P1 and P2, F1, F 2, and the two reciprocal BC 1) at two sites. A three-parameter model was inadequate to explain all traits except number of heads per plant in Inrat 69/Cocorit 71 at one site. In most cases a digenic epistatic model explained variation in generation means. Dominance effects and dominance ´ dominance epistasis (l) were more important than additive effects and other epistatic components. Considering the genotype-by-environment interaction, the interactive model was applied and found adequate in all majority of cases except spiklets per spike and grains per spike in Inrat 69/Cocorit71. The results of this study indicate that maintenance of heterozygosity is useful for exploitation of epistatic effects and adaptability to varied environmental conditions for spiklets per spike and grain per spike in the cross Karim/Ben Bechir. Estimates of narrow-sense heritability indicated that the genetic effect was larger than the environmental effect. The additive effect was the largest component of genetic effects.

Key words: Genetic effects, epitasis, genotype-by-environment interaction, heritability, Triticum durum.
 

African Journal of Crop Science ISSN: 2375-1231 Vol. 13 (3), pp. 001-013, March, 2025. Available online at www.internationalscholarsjournals.org © International Scholars Journals

Full Length Research Paper

Pollen Viability and Tube Growth Characteristics of Bambara Groundnut Cultivars: Implications for Breeding and Conservation

Oyiga Benedict Chijioke*, Uguru Michael Ifeanyi and Aruah Chinenye Blessing

Department of Crop Science, University of Nigeria, Nsukka, Nigeria.

Accepted 1 December, 2024

Two field experiments were conducted in April and August, 2007 cropping season at the Department of Crop Science research farm, University of Nigeria, Nsukka, to evaluate the pollen germination potentials and the pollen tube growth of thirteen bambara groundnut cultivars. The harvested pollen grains were exposed for 0, 5, 10 and 15 min durations to ambient conditions before in vitro germination. Pollen germination and pollen tube growth were tested using a medium containing 10 g sucrose, 100 mg/l boric acid and 300 mg/l calcium nitrate made up to 100 ml with deionized water. The results showed that cultivars, had significant effect on the pollen germination only at the late planting. The early and late planting results showed that pollens incubated immediately after harvest had the highest germination percentage, while pollen exposed for five minutes prior to germination showed very poor germination. Pollens exposed beyond five minutes after harvest did not germinate. The cultivars significantly (P < 0.05) affected the pollen tube growth at both early and late planting dates. The pollen tube growth decreased drastically with increase in duration of pollen exposure. The pollen tube had an exponential growth rate at the on set of the pollen tube growth, followed by lag and stationary growth phases in the pollen tube growth curves. The exponential, logistic and Gomperzt growth models were used to estimate the best fit model for the pollen tube growth in bambara groundnut cultivars. In the early planting, the average straightness (R2) value of these models for growth estimate were 98.4, 98.6 and 98.5%, respectively. During the late planting, the average R2 values were 91.5, 96.6 and 96.6%, respectively. The three models are therefore considered suitable for the computation of the pollen tube growth rates. The principal component and cluster analyses were used to group the cultivars in relation to the levels of pollen survival under ambient conditions. At early planting, cultivar Bg-01 had moderate surviving pollen grains while Bg- 08, Bg-09, Bg-10 and Bg-11 were found to have poor surviving pollens. At late planting, cultivar Bg-04 and Bg-07 had high survival pollens while Bg-01 had poor pollen survival.

Key words: Pollen behaviour, pollination, fertilization, Bambara groundnut, Vigna subterranea (L.) Verdc.
 

African Journal of Crop Science ISSN: 2375-1231 Vol. 13 (3), pp. 001-011, March, 2025. Available online at www.internationalscholarsjournals.org © International Scholars Journals

Full Length Research Paper

Genetic Variation in Starch Properties of Cassava (Manihot esculenta Crantz) Progenies and Parents: Implications for Dietary and Industrial Uses

Ephraim Nuwamanya1, Yona Baguma2*, Naushad Emmambux3, John Taylor3 and Rubaihayo Patrick1

1Department of Crop Science, Makerere University Kampala, P. O. Box 7062, Kampala, Uganda.
2National Crops Resources Research Institute (NaCRRI), P. O. Box 7084, Kampala, Uganda.

3Department of Food Science, Faculty of Agriculture, University of Pretoria, South Africa.

Accepted    25 November, 2024

Due to poor root quality traits in improved, disease resistant cassava (Manihot esculenta Crantz.) varieties and hence low acceptability among farmers, a study was undertaken to improve these varieties by crossing them with disease susceptible, farmer preferred local landraces. Five improved varieties and four local landraces were used and hybridisations among them were made in a poly-cross nursery block. Starch isolated from the nine cassava varieties and their F 1 progenies was analysed for physicochemical and functional properties. Significant differences were observed between varieties, progenies and within the F1 progenies. The amylose content ranging between 19.0 - 25.0% was negatively correlated to swelling power and solubility but positively correlated to starch content. Average starch granule sizes ranged between 7.0 - 12.0 mm, though smaller granules ranged between 2 6.9 mm and large granules between 13 – 20 mm. Granules were mainly truncated in shape and similar across varieties and their progenies. Individual parents had peak viscosity, set back viscosity and viscosity at breakdown higher than the progenies suggesting inherent genetic and biochemical differences among parents used in the study. Variations were also observed in the parents and progenies for starch swelling power, solubility and starch content on dry basis. Starch associated molecules such as proteins and lipids did not vary significantly but dietary fibre significantly (P< 0.05) varied both in parents and F1 families. Significant correlations (r > 0.45) were observed among starch properties including swelling power and breakdown viscosity. Based on these results, selections for lines with different starch quality and quantity properties can be made among the F1 families for future dietary and industrial uses.

Key words: Progenies, starch granules, viscosity, physicochemical properties.
 

African Journal of Crop Science ISSN: 2375-1231 Vol. 13 (3), pp. 001-007, March, 2025. Available online at www.internationalscholarsjournals.org © International Scholars Journals

Full Length Research Paper

Evaluating Absorption-Based Chlorophyll Indices for Accurate Prediction of Rice Leaf Chlorophyll Concentration

Jinheng Zhang1*, Chao Han1 and Zhiheng Liu1,2

1Institute of Eco-environment and Agriculture Information and College of Environment and Safety Engineering, Qingdao University of Science and Technology, Qingdao, Shandong 266042, China. 2College of Science, Guizhou University, Guiyang, Guizhou 550025, China.

Accepted 10 January, 2025

Our objective in this study was to develop spectral absorption indices for prediction of leaf chlorophyll concentration based on blue/yellow/red/ edge absorption spectrum. Two field experiments were conducted to study the response of chlorophyll index based on leaf absorption spectra to chlorophyll concentration in rice. The ultimate, penultimate and third expanded leaves were sampled for chlorophyll measurements and the absorption spectra of the leaves on the main stem for three rice varieties at different growth stages to select the absorption wavelength position near zero and develop better algorithms for estimating chlorophyll concentration. Some indices called blue/yellow/red/ edge absorption spectra chlorophyll index (BEACI/ YEACI/ REACI) were calculated from elected absorption wavelength positions. For the 1st experiment the correlation coefficients were similar between chlorophyll concentration and single leaf spectral absorption and between chlorophyll concentration and these indices. But the chlorophyll concentration had significant correlations (P<0.01) to these indices than single leaf spectral absorption in the 2nd experiment. The liner regression models with single leaf spectral absorption y = -2.271A480.188 + 5.574A651.232 - 2.899A753.552 - 0.269, y= -4.079A480.188 - 2.233A753.552 + 5.892A663.239 + 0.547 and y = 4.217A651.232 -0.718A753.552 - 2.897A663.239 - 0.399 had higher power prediction total chlorophyll, chlororphyll a and chlorophyll b concentrations, respectively. Compared with BEACI and REACI, stepwise regression analysis showed that YEACI630.610, YEACI570.169 and YEACI651.232 were good predictive power for predicting chlorophyll total concentration, chlorophyll a concentration and chlororphyll b concentration respectively.

Key words: Rice, chlorophyll concentration, leaf absorption spectrum, vegetation index.