ISBN-13: 9786202003148 / Angielski / Miękka / 2017 / 152 str.
The studies of the histopathology of virus infection have contributed materially to the elucidation of the biologic relations of virus to their host plants. The patterns of degenerative and deformative changes in leaf,stem and root support the concept that viruses vary in their ability to spread in the tissue of host, but they also show that the division between viruses invading the plant indiscriminately, and those invading certain tissues selectively, is not sharp, some viruses occupy intermediate positions. In meiotic studies diseased plants show reduction in number of flower buds. In flower buds numbers of female flowers are less and most of them do not show further development. In male flower pollen mother cell shows abnormalities from differentiation to telophase II some mother cells do not differentiate and they die before onset of division. Multivalent and asynchronism at metaphase I and later stage of division observed more in diseased plants. Multipolar nuclei and spindle formation caused the formation of irregular pollen. Sterile pollen may be empty or shrunken.