Exploration of Gene Action Conditioning Tolerance to Aluminum (Al) Toxicity in Tropical Maize | Chapter 4 | Contemporary Research and Perspectives in Biological Science Vol. 1

Maize is the third most important cereal crop in the world after wheat and rice. In Zambia, maize production has been reported to be increasing but its production is however hampered by both biotic and abiotic factors. Among the abiotic factors, Aluminum (Al) toxicity causes high yield losses and is directly linked to acidic soils. The application of lime can ameliorate this problem, but it is expensive for small-scale farmers. Developing maize varieties that are tolerant to Al toxicity is cheaper and feasible for small-scale farmers. The purpose of this research was to investigate the type of gene action conditioning tolerance to aluminum toxicity in tropical maize. The maize samples were obtained from the Zambia Agriculture Research Institute (ZARI). Eleven inbred lines were mated in an 8 male (4 moderately tolerant and 4 susceptible) x 3 female (resistant) North Carolina Design II. The seeds were germinated on petri dishes lined with filter paper wetted with water and placed in the germination chamber for 5 days at 25oC. The genotypes were evaluated on the 11th day. The shoot and root lengths were measured immediately after harvesting using a 30 cm ruler. Analysis of variance on root length, shoot length, number of root hairs, and root biomass was performed using a fixed model in the GenStat statistical package. Results revealed that general combining ability (GCA) effects due to both males and females were highly significant (P≤ 0.001) for root biomass. The shoot length GCA effects due to both males and females respectively were significant (P≤ 0.01). Similarly, the GCA effects due to females and males for root length were significant, P≤ 0.01 and P≤ 0.05 respectively. The genotype CML 511 had the most desirable significant GCA effect value (1.40) for root length among the male lines while CML 538 had the most desirable significant GCA effect value (0.92) among the female lines. The baker’s ratio for root length was found to be 0.49 implying that both additive and non-additive gene action was important in conditioning aluminum toxicity tolerance in tropical maize. Further work on petri studies under controlled environments and finally field conditions with additional parameters examined, such as leaf area, stress hormones, and antioxidant enzyme levels can generate more informative knowledge.

Author (s) Details

Victoria Ndeke
Zambia Agriculture Research Institute, Private Bag 7, Lusaka, Zambia.

 

Langa Tembo
Department of Plant Science, School of Agriculture Sciences, University of Zambia, P.O.Box 32379, Lusaka, Zambia.

 

Please see the book here:- https://doi.org/10.9734/bpi/crpbs/v1/1872

Line x Tester Analysis and Potential for Aluminum and Manganese Tolerance in an International Collection of Maize | Chapter 10 | Current Advances in Chemistry and Biochemistry Vol. 4

 Soil acidity is a limiting factor that has a major impact on maize yield and development. The aim of this research was to determine the breeding value of inbred lines and to assess the hybrid maize test-cross production in acid soil. A line x tester study involving 63 test-crosses formed by crossing 20 maize inbred lines with 3 testers and between testers themselves, as well as 1 standard search, was conducted in two contrasted regions with aluminium and manganese toxicity during the 2012 cropping season in Cameroon. A randomised complete block template of three replications was used to assess both acid and non-acid soil treatments with dolomitic lime. Seven hybrids were discovered that produced high grain yields (4.27 to 9.88 t/ha), had high specific combining capacity (SCA), and had a slow rate of yield loss, and were acidic soil resistant. Similarly, four inbred lines with strong general combining potential (GCA) were maintained as successful progenitors (ATP-46, 87036, and Cam Inb gp117, C4SRRA7). The GCA and SCA effects showed that genes with additive effects mediated resistance to aluminum toxicity, while genes with non-additive effects dominated on acid soil with manganese toxicity. However, a molecular characterization of the selected varieties would be needed for a possible extension.

Author (s) Details

Honoré Tekeu
Department of Plant Biology, University of Yaounde I, BP 812 Yaounde, Cameroon and Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Quebec City, QC, Canada.

Liliane N. Tandzi
Department of Agriculture, College of Basic and Apply Sciences, University of Ghana, P.O.Box 30, Legon, Ghana and Department of Crop Production Technology, College of Technology, University of Bamenda, Bambili, Cameroon.

Eddy E. M. Ngonkeu
Department of Plant Biology, University of Yaounde I, BP 812 Yaounde, Cameroon and Institute of Agricultural Research for Development (IRAD), BP 2123 Yaoundé, Cameroon.

Pierre F. Djocgoué
Department of Plant Biology, University of Yaounde I, BP 812 Yaounde, Cameroon.

View Book :- https://stm.bookpi.org/CACB-V4/article/view/910