Hematoxylin staining of seedling roots is a potential phenotypic index for screening of aluminium tolerance in rice (Oryza sativa L.)

Hematoxylin staining is an early indicator of Aluminium (Al) toxicity effects on the apices of young, developing roots and has also been used as a precocious, nondestructive way of studying Al-sensitivity in plant species. Al(H2O)63+ which is known as Al3+ is dominant in acid soil below pH 5.0 and is the most toxic form. Presence of Al in the rhizosphere of rice in acid soil restricts root growth and significantly reduces the crop productivity. In this present study, 40 rice genotypes were screened for Al-toxicity tolerance based on the hematoxylin staining of root apex of rice seedlings. The genotypes were classified into tolerant, moderately tolerant and susceptible. Based on staining intensity the genotypes IET 22838, Gobindabhog, Kalabhog, Khasha, Badshahbhog, Radhunipagal, Mohanbhog, Pusa Basmati-1, UBKVR-18, UBKVR-16, UBKVR-6 were found tolerant against Al-toxicity in the nutrient solution at 30 ppm.