Genotype x environment analysis in sunflower (Helianthus annuus) in South Africa - Schoeman, Lourens Jurgens (University of the Free State, 2003)
Sunflower (Helianthus annuus) is the most important oilseed crop in South Africa with a current demand of around 600 000 ton of seed per year. The average national yield is from 1 to 1.3 t/ha. Because sunflower is planted in the marginal maize areas, the climate and interaction varies considerably. It is this variation that present selection problems for breeders and scientists. The aim of this study was to evaluate and recommend methods of stability analyses better than the normal yield ranking and ANOVA that is mostly the tools used in selection. • For this study the trials performed by the Agricultural Research Council and its cooperators were used. Entries in the trials are commercial hybrids or registered hybrids and the results would be used to ensure quality hybrids entering the market and recommending hybrids based on yield stability and oil content. • The literature review highlighted all the studies performed recently on different traits of sunflowers. Although G x E interaction has been used in India to prove the suitability of some hybrids, no comparative studies of the stability analysis could be found that would assist a breeder or scientist. • Since the rate of success of these trials was not consistent from season to season, some locations could not be used. The hybrids were not all evaluated in successive years. Since only four entries are allowed per company in one year, the hybrids are usually rotated. Thus only six locations were used in the analysis and for the across year analysis eight hybrids were common. • Using the stability analysis of Eberhardt and RusselI, Wricke's ecovalence, Shukla and Lin and Binns superiority measure, the most stable hybrids were PAN 7351 for the 1998 /99 seasons, HV3037 for the 1999 / 00 seasons, PAN 7351 for 1998/00 and PAN7355 for 1998/99/00. According to the AMMI analysis the hybrids PAN 7355 and HV3037 were most stable for the 1998/99 seasons, PAN 7351, HV3037, PAN 7371 and AGSUN8751 were most stable for the 1999/00 seasons, SUNSTRIPE350, HYSUN 345 and PAN 7392 for 1998/00 seasons and PAN 7351, PAN 7371 and AGSUN 8751 for the combined 1998/99/00 seasons. The implementation of ASV does have an influence on the use of the AMMI analysis. The ASV showed AGSUN 8751 to be more stable than PAN 7355. • Combining all the analysis measures to make a selection, PAN 7355 and PAN 7371 were the most stable. Using the advantage of the information provided by the AMMI analysis of hybrids and their adaptation to certain locations, a high yielding stable hybrid could be selected.

Sonneblomme (Helianthus annuus), met 'n aanvraag van omtrent 600 000 ton saad per jaar, is die belangrikste oliesaad gewas in Suid Afrika. Huidiglik is die nasionale gemiddelde opbrengs tussen 1 en 1.3 t/ha en 'n bydraende faktor is die onvoorspelbare klimaat en die variasie van interaksie wat 'n kenmerk is van die marginale areas waar sonneblom geproduseer word. Dit is hierdie interaksie wat probleme met seleksie vir telers en wetenskaplikes veroorsaak. Die doelwit van die studie was om stabiliteits analises te evalueer en aan te beveel wat gebruik kan word bo en behalwe die huidige opbrengs en ANOVA wat gebruik word. • Die proewe wat deur die Landbou Navorsings Raad en die medewerkers geplant word, is gebruik. Die inskrywings in die proewe is almal kommersiële basters of reeds geregistreer en die data van die proewe word gewoonlik gebruik om nuwe basters wat die mark betree se kwaliteit te verseker gebaseer op die opbrengs en olie opbrengs. • In die literatuur oorsig word al die studies wat onlangs gedoen is op die veskillende kenmerke van sonneblomme uitgelig. Alhoewel die G x Einteraksie gebruik is in Indië om basters se aanpasbaarheid te bewys, is daar geen vergelykbare studies gedoen om telers of wetenskaplikes te help nie. • Omdat die sukses syfer nie konsekwent was tussen seisoene nie, kon sommige lokaliteite nie gebruik word nie. AI die basters het ook nie oor al die jare voorgekom nie. Die rede hiervoor is dat slegs vier inskrywings toegelaat word per maatskappy in 'n jaar wat aanleiding gee tot baster rotasie. Daar is dus net na ses lokaliteite gekyk en vir meerjarige analise is net agt basters gebruik. • Deur gebruik te maak van Eberhardt and RusseIl se regressie analise, Wricke se ekovalensie en Shukla en Linn en Binn se superioriteits meting, was die mees stabiele basters PAN 7351 gedurende die 1998/99 seisoene, HV3037 gedurende die 1999/00 seisoene, PAN 7351 gedurende 1998/00 en PAN7355 gedurende 1998/99/00. • Na aanleiding van die AMMI analise was PAN 7355 en HV3037 die mees stabiele basters vir die 1998/99 seisoen, PAN 7351, HV3037, PAN 7371 en AGSUN8751 was meer stabiel vir die 1999/00 seisoene, Sunstripe, Hysun 345 en PAN 7392 vir die 1998/00 seisoene en PAN 7351, PAN 7371 en AGSUN 8751 vir die gekombineerde 1998/99/00 seisoene. Deur die ASV te gebruik is gevind dat dit wel 'n invloed het op die AMMI analise. Die ASV het AGSUN 8751 as 'n meer stabiele baster getoon as PAN 7355. • Na aanleiding van 'n kombinasie van al die stabiliteits analises om 'n seleksie te maak, is bevind dat PAN 7355 en PAN 7351 die mees stabiele basters was. Deur van die AMMI analise se voordeel rondom inligting betreffende basters en hul aanpasbaarheid by sekere lokaliteite wat verskaf word, gebruik te maak, kan basters met hoë opbrengs en stabiliteit geselekteer word.
Dissertation (M.Sc.Agric. (Plant Sciences: Plant Breeding))--University of the Free State, 2003
Keywords: Genotype-environment interaction; Sunflowers -- Genetics; Sunflowers -- Breeding -- South Africa