The flowering characteristics and the pollen fertility in shallot line 'Chiang mai' [a variety of Allium fistulosum]

• Published in: Bulletin of the Fukuoka Agricultural Research Center (Japan) no. 27
• Main Authors: Sueyoshi, T.(Fukuoka-ken. Agricultural Research Center, Chikushino (Japan)), Shimomura, K, Koga, T, Hamachi, Y
• Format: Journal Article
• Language: Japanese
• Published: 01.03.2008
• Subjects: ALLIUM FISTULOSUM; FACULTE GERMINATIVE; FLORACION; FLORAISON; FLOWERING; GERMINABILITY; PODER GERMINATIVO; POLEN; POLLEN; TEMPERATURA; TEMPERATURE; VARIEDADES; VARIETE; VARIETIES
• ISSN: 1341-4593

We examined the flowering characteristics and the pollen fertility of the shallot line 'Chiang mai' as one of the useful genetic materials for breeding new welsh onion cultivars. 'Chiang mai' started bolting from the middle of October to early November, started flowering in the middle of May, and kept on flowering to the end of May in an open field culture. However, the start of the bolting of 'Chiang mai' was four to five months earlier than that of welsh onion cultivars, while the flowering of the 'Chiang mai' was late by over one month compared with that of welsh onion cultivars. In plastic greenhouse cultures, the flowering period of 'Chiang mai' was from early March to the end of May, and it coincided well with the flowering period of welsh onion cultivars. The pollen fertility of 'Chiang mai' in plastic greenhouse cultures was higher than the ones cultured in open fields. In plastic greenhouse cultures, the highest fertile pollen percentage of 96.0% and the highest germination percentage of 36.2% were achieved in May. The pollen fertility was influenced by the temperature, and the responses to the temperature differed between 'Chiang mai' and welsh onion cultivars. The best air condition was 30/20 deg C daytime/night temperatures for the pollen fertility of 'Chiang mai'; on the other hand 20/10 deg C was best for welsh onion cultivars. These results suggest that we can considerably extend the period of cross culturing between 'Chiang mai' and welsh onion cultivars by cultivating 'Chiang mai' in plastic greenhouses. In addition, crosses will be made more effectively by keeping the heat at not less than 15 deg C after the middle of March.