Establishment of morphological markers to differentiate male and female plants in Ailanthus excelsa Roxb. using multiple logistic regression

Abstract

Ailanthus excelsa Roxb., belongs to the family Simaroubaceae, is a fast-growing multipurpose tree, and used mainly as a source of fodder and shade. It bears male, female, and hermaphrodite flowers on separate plants. It has been observed that male plant has more leaf biomass during April-May in semi-arid regions of India (Jaipur). In its vegetative state, the sex of the tree cannot be identified. The present study has therefore been designed to investigate if there is any difference in male and female plants based on morphological descriptors namely stomata number, stomata length, stomata diameter, trichome number, trichome length, and trichome diameter. 20 plants with male flowers and 20 plants with female flowers have been studied. The data revealed that male plants have lower trichome diameter (11.91µm) than female (14.18 µm) plants. Other parameters do not show any statistically significant difference (P>0.05). The Omnibus Tests of the Model Coefficient obtained for trichome diameter (0.042) is reliable in improving the model, implying that the model is the best fit. To test the validity of this model, the Hosmer and Lemeshow test was performed, and the p-value of chi-square (0.405 > 0.05) indicates that the logistic model obtained above is the best-fit model. Further studies of trichome diameter at the seedling stage and then confirmation of plant sex at maturity level will help in establishing morphological markers in A. excelsa for identification of sex.