Screening of Al-Tolerant Sorghum by Hematoxylin Staining and Growth Response

summaryHematoxylin staining of root (hematoxylin staining method) and the growth response to Al added to the soil in pots (growth-response method) were used to select Al-tolerant sorghum. Twenty-two sorghum genotypes were screened by the hematoxylin staining method, and twelve genotypes selected were evaluated again by the growth-response method. Five genotypes (G4, HllxC8, Real 60, SPA2, and SPAD) showed consistent Al tolerance by both screening methods. Genotype C9xH13 was susceptible to Al. A significant correlation (r=0.666**) was observed between the score of hematoxylin staining method and that of relative root length (RRL). The value of RRL also showed a significant correlation with the score of hematoxylin staining (r = 0.622*). The roots of genotypes that were not stained by hematoxylin tended to have a long root in the soil with Al added.