Wednesday, November 15, 2006

Stem Reserves in Diploid, Tetraploid and Hexaploid Wheat.

Bahman Ehdaie, Univ. California-Riverside, Dept. Botany & Plant Sciences, Riverside, CA 92521-0124, Ghiath Alloush, Tashreen Univ, Dept Soil Science, Lattakia, Syria, Monica Madore, Gryndlscot Farms, RR9, Dunnville, ON N1A 2W8, Canada, and Giles Waines, Univ. Of California, Botany and Plant Sciences, 900 University Ave., Riverside, CA 92521-0124.

One accession (G3489) of wild diploid goatgrass (Aegilops tauschii, DD) with tough rachis, a tetraploid durum wheat ‘Westbred Turbo’, (Triticum turgidum L. BBAA), and four hexaploid bread wheats (T. aestivum L., BBAADD); including landrace ‘Iran No. 49’, tall old cv. ‘Maringa’, semidwarf ‘Express’, and dwarf bread wheat ‘Yecora Rojo’, were evaluated for stem length, stem weight, water-soluble carbohydrate content (WSC), WSC specific weight (stem WSC content / stem length), and WSC concentration (stem WSC content / stem weight) in well-watered and droughted field experiments with four replications across two years. Stem length at maturity was 53 cm in goatgrass, 75 cm in durum, and ranged from 47 cm (Yecora Rojo) to 87 cm (No. 49) in hexaploid wheat. Stem weight at maturity was 377 mg in goatgrass, 1843 mg in durum, and varied from 973 mg (Yecora Rojo) to 1627 mg (No. 49) in hexaploid wheat. WSC specific weight was lowest in goatgrass (1.11 mg/cm) and highest in durum (7.08 mg/cm) and ranged from 3.77 (Maringa) to 6.41 mg/cm (Yecora Rojo) in hexaploid wheat. Stem maximum WSC content was reached 10 days after anthesis in Westbred Turbo, No. 49 and G3489, and 20 days after anthesis in Express, Yecora Rojo, and Maringa. Stem maximum WSC content was102 mg in goatgrass, and 957 mg in durum wheat, and ranged from 446 (Maringa) to 695 mg (no. 49) in hexaploid wheat. Stem mobilized WSC was the lowest in goatgrass (72 mg), highest in tetraploid wheat (823 mg) and  ranged from 374 mg (Maringa) to 561 mg (Express) in hexaploid wheat. These preliminary results indicate the goatgrass DD genome may depress WSC-related traits in hexaploid wheat.   More diploid, tetraploid and hexaploid wheat accessions should be evaluated to determine the effect of the DD and BBAA genomes on WSC-related traits.   

Handout (.ppt format, 111.0 kb)