MACROSPOROGENESIS AND THE DEVELOPMENT OF THE MACROGAMETOPHYTE OF LYCOPERSICON ESCULENTUM

Abstract

Very little information concerning macrosporogenesis and the development of the embryo sac in the Solanaceae is to be found in the literature, and little indeed concerning the tomato, Lycopersicon esculentum Mill. Hofmeister (I858) made a study of the mature embryo sacs of three Solanaceous plants, Hyoscyamus orientalis, Scopolina atropoides, and Salpiglossis picta, and gave a brief description of them. Jbnsson (i88i), however, was the first to make a study of the development of the embryo sac in this family. In Saracha Jaltomato he found that the macrospore mother cell forms four daughter cells. The inner cell develops into a normal eight-nucleate embryo sac. Cases in which the embryo sac is formed in this manner have been reported by Guignard (I882) for Nicotiana tabacum and Cestrus splendens, by Soueges (1907) for Atropa belladonna, by Palm (I922) for Nicotiana tabacum Deli-tabak, and by Svensson (1926) for Hyoscyamus niger. Nanetti (I9I2) described a modified lily type of embryo sac development for Solanum muricatum, and Young (I923) found the lily type (?) of development in S. tuberosum. Mrs. Lesley (I926) has described certain of the prophase stages of macrosporogenesis in tomato. So far as the writer is aware, no detailed study has been made of the stages between diakinesis and that of the fully mature embryo sac. MATERIALS AND METHODS