SA Grain April 2017

April 2017

Screening bread wheat lines

for drought tolerance

heat is an important food and cash crop globally. The

crop is sensitive to drought and heat stresses, partic-

ularly during flowering and grain filling stages. Over

the past decade wheat production and productivity

in South Africa and most sub-Saharan African countries declined

due to several production constraints, notably by increased recur-

rent droughts associated with global climate change (Botai

et al

2016; Edossa

et al

., 2014).

South Africa is the leading wheat producer in sub-Saharan Africa.

In the country, a significant area devoted to wheat production is

lost to other alternative crops due to drought stress. The country is

increasingly reliant on wheat imports to sustain local demands for

wheat, which is negatively affecting the wheat industry (DAFF, 2013).

The use of irrigation water for wheat production is expensive, un-

sustainable and unaffordable. Also, the availability of clean water for

irrigation is critical. Other cultural practices such as mulching, fal-

lowing and use of ground cover can be applied to preserve soil

moisture. However, breeding for drought and heat tolerant cultivars

remains the most complementary, sustainable, feasible and eco-

nomic approach to drought management.

This enables development and deployment of new varieties with

high water use efficiency that produce optimum yield under mar-

ginal rainfall conditions to sustainably support wheat growers.

Adaptive characteristics selected from drought tolerant lines can be

introgressed into popular local varieties which are susceptible to

drought stress.

Breeding for drought tolerance requires dedicated research ef-

forts and collaborations among growers: Local, regional and global

governmental and NGO scientists. This allows sharing of genetic

resources, research facilities and advanced technologies (Mwadzin-

geni

et al

., 2016a).

Pre-breeding of wheat for drought

tolerance

The research team of ARC-Small Grain in collaboration with the

University of KwaZulu-Natal has initiated a drought tolerance pre-

breeding programme. The programmes undertake worldwide

collection and systematic characterisation of drought-tolerant

germplasm that will be made available to breeders and other re-

searchers in South Africa.

Under this initiative, a study was carried out to determine the level

of drought tolerance among 88 diverse bread wheat genotypes in-

troduced to South Africa from CIMMYT’s heat and drought nurser-

ies, using eight local checks.

ON FARM LEVEL

Wheat / Breeding / Drought tolerance

Seed

LEARNMORE MWADZINGENI

and

HUSSEIN SHIMELIS,

University of KwaZulu-Natal and

DR TOI J TSILO,

ARC-Small Grain

1 and 2: Screening of drought and heat

stress tolerant bread wheat genotypes at the

Ukulinga research station of the University

of KwaZulu-Natal.