The Utilization From Wild Species In Sunflower Breeding

SUMMARY

The genus Helianthus is composed of 51 species (14 annual and 37 perennial) all native to North America. Many of them were discovered and are keeping in both in situ and National Genetic stocks. The sunflower germplasm collections are available for research depending on the genetic diversity of each species and many interspecific hybrids were obtained and utilized to develop new genes. Wild sunflower species and relatives provided many gene sources for plant breeding leading to quality and yield improvement, disease resistance and tolerance for biotic and abiotic stresses such as drought tolerance, salinity and poor soil conditions, etc... These useful genes, which have obtained from the wild species broadened narrow genetic base of cultivated sunflower with supplying remaining source of desirable agronomic traits for improving cultivated sunflower. To broaden genetic material capacity, to increase heterosis, and to integrate new useful genes such as resistance, better quality and higher yield performance into developed inbred lines from wild types and derived interspecific hybrids from them in breeding programs, wild species should be certainly existed in sunflower breeding nurseries.

KEY WORDS: Sunflower, Wild Species, Resistance to Biotic Abiotic Stress,

INTRODUCTION

Sunflower (Helianthus) genus (chromosome number, n=17) belongs to Compositae (Asteraceae) family which is one of the largest and most diverse families of flowering plants. Helianthus genus is comprised of 51 species and 19 subspecies with 14 annual and 37 perennial species (Seiler, 2007). Sunflower is well adapted to extreme climate and different types of soils. The cultivated sunflower (Helianthus annuus L.) has single stem and head, and has high oil content and seed yield that improved by breeders with selection, although wild types have branched stem with multiple flowers. Sunflower is native plant of Central and Northern America and had been utilized by Native Americans for thousands of years, for food, medicines and rituals.

The genus Helianthus is an economically and evolutionarily important species that contains not only one of the most important oilseed crops, but also a number of wild species that have become increasingly important for studying of the genetics of adaptation and specification. In addition to their utility as models for studying evolutionary phenomenon, wild species of Helianthus have a considerable amount of genetic diversity that supply useful gene sources to improve cultivated sunflower. Indeed, wild Helianthus species are adapted to a broad range of habitats and have substantial variability in a number of agronomically important traits, suggesting that they might be a rich source of alleles for continued crop improvement. Major progresses on sunflower breeding with utilizing from wild types are given below.

THE USES IN QUALITY IMPROVEMENT

Higher oil content in sunflower was increased by intensive selection by breeders. Additionally, although high oleic and linoleic acid were developed by mutation, very high variability on fatty and amino acid composition was determined in wild types (Miller and Fick, 1997). Seiler (2007) examined recently two annual desert species, H. anomalus and H. deserticola, are excellent candidates for increasing oil concentration and enhancing quality such as low saturated acid based on their adaptation to desert environments. On the other hand, high variations in wild types were determined for other quality parameters such as different types of Tocopherol (E Vitamin), protein phosphorus and phospholipid content and oxidative stability (Miller and Fick, 1997).

THE USES IN SEED YIELD IMPROVEMENT & HYBRID DEVELOPMENT

After discovering CMS sources in H. petiolaris and fertility restorer genes from wild species and transferring into cultivated types, sunflower hybrids were obtained and seed yield have plateaud. Many breeders use these same sources in the sunflower breeding programs. To reduce genetic vulnerability; many new CMS and fertility restorer genes discovered and are available now for utilizing (Fick and Miller, 1997; Jan et al, 2001). On the other hand, sunflower yield reach near maximum level by the use of a CMS sources for sunflower hybrid production. Therefore, wild sunflower is likely to provide broading genetic base and the needed new genes to increase yield supplying higher photosynthesis rate, water and fertilizer use efficiency and crops biomass.

THE USES IN DISAESE RESISTANCE

Downy mildew (Plasmopara halstedii) which has many different races resulted important yield losses in the past, but metalaxyl seed treatment control 100 % this disease. However, some breaks on this resistance were determined in some countries so this pesticide is not working in some cases because of existing new races. The resistance is already determined in wild types and are using successfully in breeding programs. Most downy mildew resistance genes have been transferred from wild H. annuus, H. praecox, H. argophyllus. However, it was apparent that DM resistance was most frequent in H. argophyllus and several H. debilis subspecies, most notably H. debilis ssp. cucumerfolius (Fick and Miller, 1997; Tikhomirov and Chiryaev, 2005).

Two wild sunflower populations (SAM-1 and SAM-2) with resistance to three diseases, Alternaria leaf blight (Alternaria), Septoria leaf blight (Septoria) and powdery mildew were released as breeding populations transferring from H. tuberosus and H. resinosus (Block, 2005; Snow et al., 2006) Many wild sunflower populations detected non Sclerotinia symptoms in mature plants (Cerboncini et al. 2002; Tikhomirov and Chiryaev, 2005). Sclerotinia head rot and Sclerotinia stalk rot resistance is polygenic, and has proven much more difficult to find and transfer resistance into hybrids. Wild sunflowers H. gracilentus, H. grosseserratus, H. hirsutus, H. strumosus, H. maximiliani, H. nuttallii, H. californicus, H. schweinitzii, H. exilis appears to display an immune tolerance to Sclerotinia in USDA genetick stocks (Feng et al., 2007).

Other important sunflower diseases such as Phomopsis (Gulya,1998), black stem (Phoma) (Bert et al., 2004), Powdery Mildew (Rojas-Barros et al., 2005) and rust (Quresh et al.,1993) complete resistance were observed and transferred from wild types.

THE USES IN PEST RESISTANCE

The insects damaged in sunflower vary depending on countries. The resistances were found in some insects and these genes transferred from wild types into cultivated types. However, these resistance genes to insects related to some traits such as seed armor layer (pericarp hardened with phytomelanin content) for resistant to sunflower moth (Homoesoma nebulelum). On the other hand, several mechanisms detected in wild species such as antibiosis, chemical resitance having high concentrations of ditterpenes, sesquiterpene lactones, coumarins, ayapin, scopolotin, biological insecticide Bacillius thuringiensis acting as toxins and antidefendant for insects (Miller and Fick, 1997).

The resistance is related to flowering phenology, bud morphology and shapes of bracts effecting oviposition deterrence too. Additionally, herbivore resistance traits have introgressed from H. debilis to H. annuus and transgenic sunflower hybrids which is resistance conferred by Bt toxins and which are specific to different groups of insects developed recent years (Miller and Fick, 1997; Pilson 2000, Whitney et al, 2006).

THE USES IN HERBICIDE AND BROOMRAPE PARASITE RESISTANCE

Genetic resistance to broomrape parasite which is the biggest problem in Spain, Turkey and Balkan countries originating mainly from the wild Helianthus species, has been introduced into sunflower cultivars from early sunflower breeding programs. However, new races were appeared in recent years and covered mostly planting areas in both Turkey and Spain (Kaya et al., 2004). Wild species one of the best option sources to get resistance genes to broomrape and wild parental species such as annual wild species, H. anomalus and H. agrestis and most perennial species of wild Helianthus were immune to new broomrape races, the strain that overcame the Or5 resistance gene (Fernandez et al., 2000).

Sunflower lines developed from wild types by backcrossing method to resist some acetolactate synthase (ALS)-inhibiting herbicides such as imidazolinone (IMI) and sulfonylurea (SU) groups which appeared by natural mutation. IMI resistant hybrids increase market share rapidly in recent years because of both controlling broomrape and most problem weeds in sunflower production in Turkey (Kaya et al., 2004; Miller and Zollinger, 2004).

THE USES IN DROUGHT TOLERANCE

The sunflower is one of the most drought tolerant plants in summer crops comparable to cotton, corn, sugar beet, etc. because of extensive root system. Improved drought tolerance is one of the first objectives of breeders. Sunflower germplasm screened to identify putative traits such as stay green trait, delayed leaf senescence, transpiration efficiency and canopy morphology as well as yield performance under stress (Kiani et al., 2007). H. anomalus and H. deserticola are excellent candidates for drought tolerance genes based on their adaptation to desert environments (Seiler, 2004).

THE USES IN RESISTANCE TO OTHER STRESS FACTORS

H. paradoxus which inhabits sporadic salt marshes in US has three times more stable salt (up to 1300 mM) than cultivated sunflower (Karrenberg et al., 2006; Edelist et al., 2006). Being able to sow early to maximize the growing season and to escape drought stress has increased the importance of low-temperature tolerance in sunflower. Transcriptome activity of sunflower is related to resistance chilling and frost tolerance that observed wild species under suboptimal temperatures (Hewezi et al., 2006). On the other hand, the tolerance to boron and Molibden deficiency and the reducing of accumulation of Cd in the seed were determined in wild types and transferred into cultivated sunflower (Miller and Fick, 1997).

CONCLUSIONS

It was apparent in many studies that the improvements on yield and yield traits and quality parameters, resistance to several sunflower diseases in in both annual and perennial wild Helianthus. Therefore, sunflower breeders should continue on working wild types and interspecific hybrids to develop new genes resistant to biotic and abiotic stress conditions and for desirable agronomic traits and to broaden genetic base of their nurseries with adding new useful genes for getting high heterosis.

REFERENCES

Bert, P.F., Guillaume, D.G., Serre, F., Jouan, I., Labrouhe, D.T., Nicolas P., Vear, F. (2004) Comparative genetic analysis of quantitative traits in sunflower (H. annuus L.) 3. Characterisation of QTL involved in resistance to Sclerotinia sclerotiorum and Phoma macdonaldi. Theor Appl Genet. 109 (4):865-74.

Block, C.C. (2005) Evaluation of wild Helianthus annuus for resistance to Septoria leaf blight. Proc. 27th Sunflower Research Workshop, Fargo, ND, Jan 12-13.

Cerboncini, C., Beine, G., Binsfeld, P.C., Dresen, B., Peisker, H., Zerwas, A. and Schnabl H. (2002) Sources of resistance to Sclerotinia sclerotiorum (Lib.) de Bary in the natural Helianthus gene pool. Helia 25, 167-176.

Edelist C, Lexer C, Dillmann C, Sicard D, Rieseberg LH. (2006). Microsatellite signature of ecological selection for salt tolerance in a wild sunflower hybrid species, Helianthus paradoxus. Mol Ecol. 15(14):4623-34.

Feng, J., Seiler, G.J., Gulya Jr, T.J., Li, C., Jan, C.C. (2007). Sclerotinia stem and head rot resistant germplasm development utilizing interspecific amphiploids. 29th Sunflower Research Workshop, January 10-11, 2007, Fargo, ND.

Fernández-Martínez JM, Melero-Vara J, Muñoz-Ruz J, Ruso J, Domínguez J. (2000). Selection of wild and cultivated sunflower for resistance to a new broomrape race that overcomes resistance to Or5 gene. Crop Science. 40:550–555

Fick, G.N. and Miller, J.F. (1997) Sunflower Breeding. In: A.A. Schneiter (ed.) Sunflower Technology and Production. ASA. SCSA. And SSSA Monograph. No: 35. Madison, WI, USA. 395-440.

Gulya, T. J. (1998) Evaluating sunflower germplasm for resistance to Phomopsis stem canker. Proc. 20th Sunflower Research Workshop. Fargo, ND. January 15-16. 92-94.

Hewezi T, Leger, M., El Kayal, W., Gentzbittel, L. (2006) Transcriptional profiling of sunflower plants growing under low temperatures reveals an extensive down-regulation of gene expression associated with chilling sensitivity. J Exp Bot. 57(12):3109-22.

Jan, C.C., Vick, B.A. and Miller, J. F. (2001) Alternative CMS and restoration sources for sunflower improvement. Proc. 23rd Sunflower Research Workshop. Fargo, ND. January 17-18. 160-163.

Kaya, Y. Evci, G. Pekcan, V and Gucer, T. (2004) Determining new broomrape infested areas, resistant lines and hybrids in Trakya Region of Turkey. Helia. 27: 40. 211-218.

Karrenberg S, Edelist C, Lexer C, Rieseberg L. (2006) Response to salinity in the homoploid hybrid species H. paradoxus and its progenitors H. annuus and H. petiolaris. New Phytol. 170(3):615-29.

Kiani P.S., Grieu, P., Maury, P., Hewezi, T., Gentzbittel, L., Sarrafi, A. (2007) Genetic variability for physiological traits under drought conditions and differential expression of water stress-associated genes in sunflower. Theor Appl Genet. 114 (2): 193-207.

Miller, J.F., Zollinger, R. (2004) Utilization of cross-resistance to create herbicide-resistant sunflower hybrids. Proceedings Sunflower Research Workshop. Fargo, ND.

Pilson D. (2000) Herbivory and natural selection on flowering phenology in wild sunflower, Helianthus annuus. Oecologia 122: 72-82

Quresh, Z., Jan, C.C., and Gulya T.J.. (1993). Resistance to sunflower rust and its inheritance in wild sunflower species. Plant Breeding 110:297–306.

Rana, J. S., Sheoran, R. K. (2004) Evaluation of sunflower, Helianthus annuus L. hybrids against insect pests in semi-arid tropics. J. of Oilseeds Research, 21(2):374-375.

Rojas-Barros, P., Chao-Chien J., and T. J. Gulya. (2005). Transferring Powdery Mildew Resistance Genes From Wild Helianthus Into Cultivated Sunflower. In Proc. of Sunflower Res. Workshop. Fargo, Natl. Sunf. Assoc., Bismarck, ND.

Seiler, G.J. (2004) Wild H. anomalus and H. deserticola from the desert southwest USA: a potential source of stress genes for cultivated sunflower. International Crop Science Congress. 26 Sep – 1 Oct. Brisbane, Australia.

Seiler G.J. (2007) Wild annual Helianthus anomalus and H. deserticola for improving oil content and quality in sunflower. Industrial Crops and Products. 25(1), 95-100.

Snow, A.A., Pilson, D., Rieseberg, L.H., Paulsen, M.J., Pleskac, N., Reagon, M.R.,

Sujatha, D.E. and Prabakaran, A. (2006) Ploidy Manipulation and Introgression of Resistance to Alternaria Helianthi from Wild Hexaploid Helianthus Species to Cultivated Sunflower (H. annuus L.) Aided by Anther Culture. Euphytica. 201-215(15)

Whitney KD, Randell RA, Rieseberg LH. (2006) Adaptive Introgression of Herbivore Resistance Traits in the Weedy Sunflower Helianthus annuus. Am Nat. 28; 167-177.

Tikhomirov V.T. and Chiryaev P.V. (2005) Sources of resistance to diseases in original material of sunflower. Helia, 28(42): 101-106.

YUKARI