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Meiotic Behavior of a Disomic Nematode‐Resistant Sugarbeet 1
Author(s) -
Yu M. H.
Publication year - 1978
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci1978.0011183x001800040023x
Subject(s) - biology , meiosis , nematode , heterodera schachtii , ploidy , pollen , chromosome , heterodera avenae , botany , selfing , heterodera , genetics , gene , ecology , population , demography , sociology
A disomic (2n = 18) sugarbeet ( Beta vulgaris L.), selection 51501, resistant to cyst nematode ( Heterodera schachtii Schm.), was recovered from the progenies of resistant alien addition lines. Meiosis of this plant was not normal and gave univalents, laggards, fragments, bridges, unequal chromosome distribution, restitution nuclei, and “carry‐over” AI bridges. Two heterozygous paracentric inversions were evident. These aberrations were not necessarily related to the nematode resistance. Nuclear restitution occurred in either the first or second division, or both; consequently, diploid and tetraploid gametophytes were produced. More than 25% of the pollen aborted. The preliminary findings showed that nematode resistance was transmitted to the progenies through the pollen and ovules at an equally low rate (13%). A multiple gene hypothesis of three complementary dominant genes was proposed to interpret the phenomenon of the low frequency transmission of nematode resistance.