Maataloustieteellinen A ikakauskirja Vol. 60: 255—259, 1988 Breeding sunflower cultivars for the northern latitudes WALTER DEDIO Agriculture Canada Research Station, Box 3001 Morden, Manitoba, Canada. ROG IJO Abstract. Development of short season sunflower hybrids has been the main objective of the Canadian sunflower breeding program. A gene pool created with 50 lines extracted from USSR open-pollinated varieties provided a good source of early inbred lines. The gene pool produced the lines CM447, CM469 and CM497 which were the basis for the superior early parental lines. Another early line, CM594, was extracted from Armavirec. CM447 and CM594 were converted to the cytoplasmicmale sterile (cms) form, while CM469 and CM497 were used in the development of fertility-restorer lines. Hybrids from these lines and in combination with HA3OI, HA232, and NS39 resulted in up to 15 days earlier maturity than the standard hybrids, with good oil content, disease resistance and lodging resistance. An early dwarf hybrid. Sun- wheat, developedby SeedTec shows good performance in late seeded tests, but it requires higher plant population and a narrow row spacing. Index words: sunflower, early hybrids, male-sterile forms, restorer lines, dwarf hybrid Introduction The sunflower crop (Helianthus ammus L.) is rather late maturing, usually requiring over 120 days to reach physiological maturity. Often the crop is not ready for harvesting be- fore there is snow on the ground with sub- freezing temperatures. In Canada the cultiva- tion of sunflowers has been limited to southern Manitoba in the prairies, where growing degree days above 5.5°C are at least 1 400 for the period May 1 to Sept 30. Considerable variability in maturity require- ment exists in the sunflower germplasm. This has been exploited by the Soviet breeders who through their extensive breeding program de- veloped cultivars that are suitable over a wide area in their country. Some of the cultivars mature up to 14days earlier than thepopular Peredovik. Some early cultivars such as Kras- nodarets, Saliut, Armavirec and Chernianka 66 have been licensed for production in Cana- da. Open-pollinated cultivars are fairly heter- 255 JOURNAL OF AGRICULTURAL SCIENCE IN FINLAND https://www.c-info.fi/en/info/?token=H9e0sp7XS2Q0wRl5.AX7vczRzkquMUUMOJZGX2A.e7LBxXi_TsqivCcb0sSoF1GlbDmmrFz-uMQW8PKh-spJc1qLlzxJrJL_oGozMWXXDT6eO6sq3-J3ueeKnXGPPK0l0Ag_6tVE2YhC9geXAEjWlkYQebyTXZf31pKgRfvk8Kf-3vBwrlS2tcu_IDTI3OCVnfT1tLvbrh4 ogenous, thus the maturity is uneven, result- ing in delayed harvesting. With the discovery of the cytoplasmic male sterility-fertility restorer system (Leclerq, 1971), it has be- come possible to obtain genuine hybrids that are more uniform in maturity and yield con- siderably more than the open-pollinated cul- tivars. With the hybrids it was also easier to incorporate disease resistance. With this sys- tem we have established a program of de- veloping early maturing hybrids that could ex- tend sunflower production beyond 55° lati- tude with less than 100 frost-free days. This manuscript deals with the achievements ob- tained so far in this program. Results are also presented of tests with a new early dwarf hybrid, Sunwheat, developed and distributed by a commercial company, SeedTec. Materials and methods Most of the sources of early maturity come from the USSR open-pollinated cultivars such as Karlic, Armavirec, Krasnodarets, Tam- bovsky Early, Saliut and Chernianka 66. Inbred lines were extracted from these culti- vars by selfing for at least 3 generations. Some of these lines had rust (Puccinia helianthi Schw.) resistance incorporated into them early in our breeding program. A gene pool was also established by pooling 50 inbred lines from various sources. Although these lines were selected mostly for superior agronomic characters, some were early. The lines were al- lowed to interpollinate for 3 generations be- fore being selfed for 3 generations and then selected for desirable types (Dedio and Enns, 1976). From the gene pool, 130 S 3 lines were selected, which traced back to 56 S 0 plants. These were subsequently tested for their com- bining ability as males by crossing them onto a cytoplasmic male sterile Krasnodarets. Since the hybrids were sterile, two rows of normal Krasnodarets were planted alternately with two rows of the experimental hybrid in 1974. Krasnodarets supplied the pollen to fertilize the sterile hybrids and was used to compare the performance. From the 130 hybrids, 51 were retested in 1975. From the 51 lines, several lines were select- ed to be converted to the cms or restorer form or to be used to develop other lines. Lines were converted to the cms form by backcrossing for several generations or were converted to the restorer form by using American restorer line RHA 274 or their restorer composite as a donor of fertility restorer genes. The donor parent also provided the recessive branching character and resistance to certain diseases such as downy mildew (Plasmopora halstedii). Several generations of selfing were required following the cross to obtain the fertility- restorer and other genes in a homozygous con- dition. Additional restorer lines were obtained by intercrossing different restorer lines or a restorer line with a normal line to combine the desirable characters. Combinations of Morden inbreds were evaluated as hybrids. These inbreds were released as germplasm for the use of other breeders (Dedio and Hoes 1985, 1988). Ear- ly inbred lines from United States and Yugos- lavia were also evaluated in hybrid combina- tions with the Morden lines. The foreign lines evaluated were HAI24, HA232, HA3OI and NS39. The hybrids were tested during the years 1982 to 1987 at a plant population of approximately 50,000 per hectare. Open-pol- linated cultivars, Krasnodarets, Saliut and Sputnik were used as checks in 1974 and 1975, while hybrids Cargill 207, and IS 7111 served as checks in 1986 and 1987. Private breeders have also been involved in breeding of early maturity sunflower hybrids. A new type of early dwarfhybrid, Sunwheat, a sunflower hybrid less than 1 m in height was released by a commercial company, SeedTec. It was tested at 5 locations in Manitoba in 1986—87 with higher populations of 84,000 plants per hectare as recommended by the company. Results and discussions The average yield of the test hybrids with 256 Table I. Performance of hybrids with Krasnodarets as the tester female parent in 1974. Flowering days Maturity days Yield Oil from seeding from seeding kg ha-' % Tests hybrids (mean of 130) 62.5 111 2 230 47.6 Krasnodarets 62 111 2 107 45.1 Sputnik 67 116 1 877 45.8 Krasnodarets as the tester female parent was 6 % above the check cultivar Krasnodarets (Table 1). Average maturity was close to that of Krasnodarets. More importantly the oil content averaged 2.5 percentage points above the check cultivar. The retested hybrids yield- ed 19.6 % higher than Krasnodarets and 17.2 % higher than Saliut in the 1975 tests (Table 2). Yield increases over Krasnodarets varied from —l7 to 45 %. The oil content averaged 3.1 percentage points above Krasnodarets and 1.5 percentage points above Saliut. From the gene pool, three lines were select- ed that had the best combining ability and were early were coded as CM447, CM469 and CM497. CM447 was released as a female line (Dedio and Hoes, 1985). Another line, hav- ing CM447 in its pedigree, CM597, was also released as a female, (Dedio and Hoes, in press). CM497 was used to produce the restorer line CM592 (Dedio and Hoes, 1985). The most promising line has been CM469 from which several restorer lines have been released including CMSB6, CMSB7 (Dedio and Hoes, 1983) and CMS9O and CMS9I (Dedio and Hoes, 1985). A cross of restorers derived from CM469 and CM497 yielded an early restorer CM596 (Dedio and Hoes, in press). When selections were made from crosses the primary objective was to select for early maturing lines. Several progeny lines were several days earlier than eitherof the parents. Such was the case with the lines CMS9I and CM596. A trait that is important to sunflower grow- ers all over the world is resistance to lodging. CM469 proved to be a good source of this trait, resulting in the good lodging resistance Table 2. Performance of hybrids with Krasnodarets as the tester parent, retested in 1975. Flowering Yield Oil days from kg ha -1 % seeding Test hybrids (mean of 51) 66.5 2 899 50.7 Krasnodarets 66.5 2 425 47.6 Saliut 66 2 473 49.2 of the lines CMS9O and CMS9I. An interest- ing line, CM595, has been developed by cross- ing a CM469 derived line with a selection from Krasnodarets. In addition to being early and lodging resistant, it is also dwarf. CM595 has just been converted to the cms form, but it has been tested for combining ability as a male only. An early line, CM594 was extracted from an open-pollinated cultivar, Armavirec. It is one of the earliest lines which has good com- bining ability. The foreign lines, HA232, HA3OI and NS39, also resulted in high yielding, early hybrids. They combined well with the lines CMS9I, CM594, CM595, CM596 and CM597 (Table 3). Although the yields were lower than widely grown later maturing hybrids in the traditional sunflower area, they were up to 2 weeks earlier in maturity, making them suita- ble for shorter growing seasons. More testing of the early hybrids is needed. There was a larger spread in the maturity time in 1987 than in 1986. This may have been due to cooler September temperatures in 1987. The maturity data reported are physiological maturity, which is the stage where food syn- thesis in the achene ceases and frosts at this 257 Table 3. Performance of early experimental hybrids relative to the means of commercially grown check hybrids Cargill 207 and IS 7111. Test Yield Maturity Height Oil Con- Hybrid % Days cm tent % 1986 CM447 X CM596 75 9 —l9 1.6 HA3OI X CM596 82 7 —5O 0.3 NS39 X CM596 88 9 —22 —6.2 HA232 X CMS9I 90 4 3 3.1 CM447 X CM595 83 5 —27 0.0 1987 CM594 X CM595 78 —l2 —56 0.3 HA232 X CM595 79 —l5 —43 3.5 HA232 X CMS9I 89 —lO 7 2.0 CM594 X CM596 70 —l2 —35 1.4 CM597 X CM596 66 5 —33 2.4 NS39 X CM596 88 —l3 —l9 —7.0 Table 4. Comparison of Sunwheat with check hybrids in 1986—1987 tests in Manitoba, Canada. Yield Oil Maturity Height Hybrid kg/ha (SE) % Days cm Cargill 207 3 085 (150) 44.0 119 182 IS 7111 2 796 (287) 49.5 116 160 IS 7101 2 621 (201) 46.6 115 165 Cargill 205 2 613 ( 79) 48.0 118 169 Sunwheat 101 2 459 (402) 43.3 109 100 stage would do no harm. For harvesting pur- poses, however, at least 3 more weeks are re- quired to obtain a moisture content of 10 % or less. The length of the dry-down period varies greatly from one cultivar to another, with some hybrids drying down as much as 10days earlier if time from flowering is con- sidered. The performance of Sunwheat throughout the province has been quite variable, but in general it yielded lower than many of the con- ventional hybrids (Table 4). In contrast to other cultivars where yields declined with a de- lay in seeding, the yield of Sunwheat increased by an average of 20 % with June 12 and 13 seedings compared to the May 19 and 20 seed- ings in 1986 and 1987, respectively. Sunwheat is a dwarf cultivar making it less susceptible to lodging. By growing it at a higher popula- tion and in narrow rows, the heads are smaller resulting in a faster dry down. The small heads also make it possible to harvest with conven- tional small grain harvesting equipment. Other early maturing germplasms from ear- ly open-pollinated varieties are available and hybrids that reach physiological maturity in less than 100 days, which is about 20 days earlier than the conventional varieties, have been obtained. Unfortunately, they do not have desirable agronomic characteristics such as resistence to lodging and good yield. Other sources of early maturity are the wild H. an- nuus and other wild Helianthus species. These sources have not yet been exploited. 258 6 References Dedio, W. and H. Enns. 1976. Progress Report on breeding for early hybrids. Proc. Sunflower Forum. Jan. 8, 1976, Sun. Assoc. Am. p. 3—4. and J.A. Hoes. 1983. Registration of sunflower restorer parental lines CMSB6 and CMSB7. Crop Sci. 23: 169. and J.A. Hoes. 1985. Registration of sunflower parental lines CM447, CMSBB, CMS9O, CMS9I and CM592. Crop. Sci. 25: 890. and J.A. Hoes. 1988. Registration of sunflower parental lines CM593, CM594, CM596 and CM597. Crop Sci. (in press). Leclercq, P. 1971. La sterilite male cytoplasmique to du tournesol. I. Premieres etudes sur la restauration de la fertilite. Ann. Amelior. Plant. 21: 45—54. SELOSTUS Auringonkukan jalostaminen pohjoisille leveysasteille Walter Dedio Agriculture Canada Research Station, Box 3001, Morden, Manitoba, Canada. ROG IJO Auringonkukan jalostusohjelmanpäätavoite Kanadassa on lyhyen kasvukauden oloihin sopeutuneiden hybridi- lajikkeiden kehittäminen. Aikaisten sukusiitoslinjojen lähteenä on käytetty neuvostoliittolaisista vapaapölytys- lajikkeista valittuja 50 linjaa. Tästä aineistosta polveu- tuvat linjat CM447, CM469 ja CM497. Aikainen linja CM594 on valittu Armavirec-lajikkeesta. CM447 ja CM594 on muutettu koirassteriileiksi (tms) linjoiksi, kun taas linjoja CM469 ja CM497 käytettiin lisääntymiskyvyn palauttajain, restorerien, kehittämisessä. Risteyttämällä näitä linjoja keskenään ja ulkomaisten alkuperien HA3OI, HA232 ja NS39 kanssa saatiin jopa 15 päivää verrannehybridejäaikaisempia alkuperiä, joiden öljypitoisuus on korkea ja jotka ovat taudinkestäviä ja lakoontumattomia. Aikainen kääpiö-hybridi Sunwheat, jonka on laskenut kauppaan SeedTec-yhtiö, menestyy hyvin myöhään kylvettynä, mutta vaatii tiheän kasvuston ja kapean rivivälin. 259