Coleoptile length comparison of three winter small grain cereals adapted to the Great Plains

Successful crop stand establishment is critical to realize high yield potential, which is dependent on depth of seed placement to access soil moisture. The coleoptile determines sowing depth by its length and ability to emerge from depth. This study was conducted to assess coleoptile length among three sets of three Great Plains winter small grain cereals-wheat (Triticum aestivum L.), barley (Hordeum vulgare L.) and triticale (X triticosecale Wittm.)-and to evaluate the effect of the Rht-B1b dwarfing allele on coleoptile length in wheat and triticale. Fifty seeds of each genotype were sown in wet germination paper in two replications utilizing a randomized complete block design, which were placed in dark growth chambers at 25 degrees C. Measurements were conducted after 7 d, and analysis of variance and comparison of least square means for coleoptile length among and within each set of genotypes were performed in Statistix 8.1 software using Fisher's protected least significance difference at the alpha = 0.05 significance level. Results revealed that triticale had the longest coleoptiles, which were significantly longer (P < 0.05) than those measured in both barley and wheat. Additionally, significant variation in coleoptile length (P < 0.05) was also found within each set of wheat (3.52-6.41 cm), barley (4.32-6.63 cm) and triticale (4.05-6.92 cm) genotypes, respectively. These findings confirm other reports that the presence of the Rht-B1b allele was pleiotropic for coleoptile length, but development of semi-dwarf wheats with longer coleoptiles is possible if breeders deploy concurrent selection strategies.

Automated summary

The study assessed coleoptile length among Great Plains winter small grain cereal crops and found triticale had the longest coleoptiles, significantly longer than barley and wheat. Significant variation in coleoptile length was also found within each set of wheat, barley, and triticale genotypes.