Revista Chapingo. Serie horticultura
versão impressa ISSN 1027-152X
AYALA-ARREOLA, J. et al. Scion-interstock relationships and anatomical and physiological leaf characteristics of four avocado genotypes. Rev. Chapingo Ser.Hortic [online]. 2010, vol.16, n.2, pp. 147-154. ISSN 1027-152X.
The influence of interstock in anatomical and physiological leaf characteristics were evaluated in 'Hass', 'Fuerte', 'Colín V-33' and 'Duke 7' used as interstocks and final grafts. Stomatal density, epidermal cell density, stomatic index and stomata polar diameter were assessed in leaf blade. In cross sections of the central vein and petiole of the leaf: area, perimeter, length of the minimum and maximum axis, roundness index and Feret diameter of xylem vessels were determined. Thickness of the upper and lower epidermis and thickness of palisade parenchyma I layer were measured in leaf cross sections. Physiological variables were CO2 assimilation rate, stomatic conductance, CO2 internal concentration, stomatic resistance, transpiration rate and leaf temperature. 'Colín V-33' as interstock induced higher stomatal and epidermal cell density and thicker palisade parenchyma I. In the intra genotype comparison, 'Hass' and 'Fuerte' with interstock increased stomatal density 18.8 and 17.8 %, respectively, while 'Duke 7' caused a 25.4 % reduction. Epidermal cell density increased in 'Fuerte' (23.3 %) with the presence of the interstock. 'Fuerte' and 'Duke 7' with interstock increased the thickness of the lower epidermis in 14.9 and 12.1 %, respectively, while 'Hass' and 'Colín V-33' with interstock reduced epidermis thickness by 19.5 and 1.0 %, respectively. 'Hass' as interstock promoted a higher CO2 assimilation rate than that promoted by 'Duke 7'. 'Colín V-33', as a rootstock, showed lower stomatic resistance than 'Duke 7'.
Palavras-chave : CO2 assimilation; stomatal resistance; Persea americana; stomatal density; vascular system.