Portal de Periódicos da CAPES

Studies on Development of the Embryo Sac and Its Abnormality in the Triploid Apple Cultivar ^|^lsquo;Mutsu^|^rsquo;

1988; Japanese Society for Horticultural Science; Volume: 57; Issue: 3 Linguagem: Inglês

10.2503/jjshs.57.366

1880-358X

Masashi Sato, K. Kanbe, Shoichi Nakagawa, Eiji Yuda, Shingo Fukunaga,

Plant Physiology and Cultivation Studies

To study the process of embryo sac development and its abnormality in a triploid apple cultivar, developing ovules of triploid 'Mutsu' were histologically compared with those of diploid 'Golden Delicious' in a period from 1 or 2 days before anthesis through 20 days after cross-pollination.1. Mature egg apparatuses were found in embryo sacs of 'Golden Delicious', whereas they were not observed in 'Mutsu' on the day of anthesis. The percentage of embryo sacs containing a mature egg apparatus of synergids, egg and polar nuclei, and fertilized egg and polar nucleus was 85.4% in 'Mutsu', while it was 98.0% in 'Golden Delicious' 3 days after anthesis.2. The percentage of double-fertilized ovules was about 85-86% in 'Mutsu' and 97-99% in 'Golden Delicious'.3. The percentage of ovules having a non-divided zygote and/or primary endosperm nucleus, vas as high as 19.4-26.9% in 'Mutsu', whereas it was 1.9-6.2% in 'Golden Delicious'. Ovules containing non-divided zygotes and primary endosperm nuclei were most frequently observed in 'Mutsu'.4. The percentage of ovules having the embryo and/or endosperm degenerated at an early stage of development was 8.9% in 'Alutsu', but 2.5% in 'Golden Delicious'.5. In triploid 'Mutsu' the percentage of ovules lacking fertilization clue to imperfect female gametophytes was about 13%, and that of ovules containing an abnormal embryo and/or endosperm was approximately 28-36%. Such abnormal ones usually showed zygotes and primary endosperm nuclei without nuclear division.