A COMPARATIVE-STUDY OF THE TAPETAL BEHAVIOR IN MALE FERTILE AND MALE-STERILE IRIS-PALLIDA LAM DURING MICROSPOROGENESIS

Two different clones of Iris pallida Lam., male-fertile and male-steri le, are present in Tuscany. In the male-sterile clone, the degeneratio n of the fertile tissue takes place at the dyad or tetrad stage. Compa rative analysis of the anthers, during microsporogenesis, revealed tha t the tapetal cells of the two clones behaved differently. In the male -fertile line the tapetum presents developmental stages ending in its final degeneration and disappearance. On the contrary, in the male-ste rile line the tapetum maintains its initial aspect until necrosis take s place at the dyad or tetrad stage. The persistence of the inner tang ential wall of the cells seems to hinder the orbicules from reaching t he locular cavity.