Variation and agronomic potential of semi-arid wheat germplasm in the Limpopo Province of South Africa
Variation and agronomic potentialof semi-arid wheat germplasm in the Limpopo Province of South Africa H. Shimelis and M.D. Laing African Centre for Crop Improvement (ACCI)School of Agricultural, Earth and Environmental Sciences University of KwaZulu-Natal Republic of South Africa firstname.lastname@example.org
IMPORTANT POINTS 47 CIMMYT Drought Tolerant (DT) lines & 2 local wheat cultivars screened for yield and components in a semi-arid agro-ecology in the northern South Africa Best yield at 8.6 t ha -1 vs. 3.74 t ha -1 of local check 5 DT lines with excellent yield and agronomic traits are selected for direct production in Limpopo, South Africa Several lines with extreme performance on important traits to be used as donor parents in backcross breeding
INTRODUCTION Drought is a major limiting factor of wheat production globally Successful breeding for drought resistance would be extremely valuable Different traits are available that are consistently associated with higher grain yield under drought conditions
INTRODUCTION Drought is one of the major constraints of wheat production in South Africa. Limpopo Province - semi-arid = 300-400 mm p.a. rainfall, restricting wheat production. CIMMYT has developing candidate genotypes for semi-arid and unfavorable environments. Exploiting the genetic potential of these germplasm for improved drought and heat resistance is important for SA.
OBJECTIVES1. To determine genetic variation and potential of semi-arid wheat germplasm for yield and important agronomic traits in Limpopo Province.2. Select suitable parents and introgress traits into desirable genetic background to develop drought and heat stress resistant cultivars.
MATERIALS AND METHODS OBJECTIVES49 diverse bread wheat lines used; 47bred for semi-arid environments andtwo commercial local checks(SST822, SST825) included ascomparative controls.
MATERIALS AND METHODS Field experiments conducted (2007 and 2008) in Limpopo Province at the Experimental Farm of the University of Limpopo.
MATERIALS AND METHODS Design: partially balanced lattice – 7 incomplete blocks, 3 replications Parameters measured: Yield and agronomic traits linked with Early or Terminal stress resistance Data analysis: Agrobase Gen II and SAS Lattice procedure
RESULTS AND DISCUSSIONObserved variations:• days to heading 52.62 - 98.91 days• plant height 570 – 989.5 mm• tiller numbers 8 - 24 per plant• days to maturity 126 - 147 days• spikelet length 53.3 - 130 mm• No. spikelets per spike 11 - 31• No. kernels per spike 8 - 46• hundred kernel weight 3.33 - 6.34 g• Yield 2.42 - 8.58 t ha-1
Key performers Early Heading (days) 304=53, 338=79 vs. 301=95 ; 321=99 Reduced Plant Height (mm) 311 & 307=580, 303=640 vs. 348=980 High Tiller Numbers 319=24, 311=22 vs. 304=8 Maturity Date (days) 325=126; 302, 326=127, vs. 301=147 Spike Length (mm) 323=130; 317, 322=120 vs. 334=70 Spikelets Per Spike 323=31, 307=30, 322=27 vs. 310, 343=11
Key performers Kernels Per Spike 323=46; 326, 334, 336=44 vs. 317=8 Hundred Kernel Weight (g) 336=6.34; 305, 322, 323, 324=5.3 vs. 321=4 High Yield (t ha-1) 336=8.6, 326=8.2; 302, 338=8 vs. 337=2.4
• Seed yield positively correlated (P<0.01) with tiller number, spike length, number of spikelets per spike, and hundred kernel weight.• Lines 336, 326, 302, 338 and 322 selected with excellent yield and agronomic traits under semi-arid conditions and can be screened for flour quality
Figure. Rotated principal component scores and percentexplained variance showing similarities among 49 entriesof T. aestivum
Some lines have good agronomic attributes e.g.304 is early maturing (53 d), 307 and 311 withshort plant height (570 mm) but low tillering andlow yield. These and other lines could serve asdonor parents.Further improvement of wheat for water limitedand marginal environments is possible using thegermplasm characterized here
Future ResearchFurther evaluation and selection of best lines xAgro-ecologies in the ProvinceScreen for quality traits and drought toleranceBackcrosses: earliness x good yield & agronomictraitsTest other sources of drought or heat shockresistant germplasm
ACKNOWLEDGMENTS• The National Research Foundation (NRF)• CIMMYT• The Generation Challenge Program (GCP)