Genetic parameters for drought-tolerance in cassava

The objective of this work was to evaluate the effect of drought on genetic parameters and breeding values of cassava. The experiments were carried out in a completely randomized block design with three replicates, under field conditions with (WD) or without (FI) water deficit. Yield of storage roots (RoY), shoot (ShY), and starch (StY), as well as the number of roots (NR), and root dry matter content (DMC) were evaluated in 47 cassava accessions. Significant differences were observed among accessions; according to heritability, these differences had mostly a genetic nature. Heritability estimates for genotypic effects (h g 2 ) ranged from 0.25±0.12 (NR) to 0.60±0.18 (DMC), and from 0.51±0.17 (NR) to 0.80±0.21 (RoY and StY) for WD and FI, respectively, as a consequence of greater environmental influence on WD. Selective accuracy was lower in WD, and ranged from 0.71 (NR) to 0.89 (RoY, DMC, and StY). However, genetic gains were quite high and ranged from 24.43% (DMC) to 113.41% (StY), in WD, and from 8.5% (DMC) to 75.70% (StY) in FI. These genetic parameters may be useful for defining which selection strategies, breeding methods, and experimental designs are more suitable to obtain cassava genetic gains for tolerance to drought.

[1]  Hikmet Budak,et al.  Drought Tolerance in Modern and Wild Wheat , 2013, TheScientificWorldJournal.

[2]  S. Gebeyehu,et al.  Generation mean analysis and heritability of drought resistance in common bean (Phaseolus vulgaris L.) , 2013 .

[3]  John G. Holden,et al.  A fractal approach to dynamic inference and distribution analysis , 2013, Front. Physio..

[4]  Martin Fregene,et al.  Phenotypic approaches to drought in cassava: review , 2012, Front. Physiol..

[5]  H. Araméndiz,et al.  GANANCIA GENÉTICA ESPERADA EN LA SELECCIÓN DE ACACIA (Acacia mangium WILLD.) EN CÓRDOBA (COLOMBIA) , 2010 .

[6]  V. Borges,et al.  Seleção de clones de batata-doce pelo procedimento REML/BLUP - doi: 10.4025/actasciagron.v32i4.4837 , 2010 .

[7]  E. Farshadfar,et al.  Inheritance of drought tolerance in chickpea (Cicer arietinum L.) using joint scaling test. , 2008 .

[8]  M. El-Sharkawy.  Physiological characteristics of cassava tolerance to prolonged drought in the tropics: implications for breeding cultivars adapted to seasonally dry and semiarid environments , 2007 .

[9]  M. D. V. Resende,et al.  PRECISÃO E CONTROLE DE QUALIDADE EM EXPERIMENTOS DE AVALIAÇÃO DE CULTIVARES , 2007 .

[10]  .. E.A.Akinrinde,et al.  Effect of soil moisture stress on growth and yield of cassava in Nigeria. , 2007 .

[11]  U. Gullberg,et al.  Quantitative trait loci controlling cyanogenic glucoside and dry matter content in cassava (Manihot esculenta Crantz) roots. , 2007, Hereditas.

[12]  S. Long,et al.  Food for Thought: Lower-Than-Expected Crop Yield Stimulation with Rising CO2 Concentrations , 2006, Science.

[13]  J. Cock,et al.  Leaf retention and cassava productivity , 2006 .

[14]  John Doebley,et al.  Maize association population: a high-resolution platform for quantitative trait locus dissection. , 2005, The Plant journal : for cell and molecular biology.

[15]  M. El-Sharkawy.  How can calibrated research-based models be improved for use as a tool in identifying genes controlling crop tolerance to environmental stresses in the era of genomics—from an experimentalist's perspective , 2005, Photosynthetica.

[16]  E. Farshadfar,et al.  Estimation of genetic parameters and chromosomal localization of QTLs controlling agro-physiological indicators of drought tolerance in agropyron using wheat-agropyron disomic addition lines. , 2014 .

[17]  Y. Baguma,et al.  Evaluation of Ugandan cassava germplasm for drought tolerance , 2013 .

[18]  A. Dixon,et al.  Effect of soil moisture stress on growth and yield of cassava in Nigeria. , 2007, Pakistan journal of biological sciences : PJBS.