Hyper-tetraploids in pea

Summary Cytomorphologically, five hypertetraploids; three hexasomic (4n+2=30), one double pentasomic (4n+1+1=30) and one multiple aneuploid tetraploid (4n+2+1+1+1=33), where isolated in the C₃ generation of pea autotetraploids. Plants with 30 chromosomes were morphologically very distinct from their euploids and characterized by variation in plant height and morphology of leaves. Hexasomic and double pentasomic tetraploids were characterized by the presence of a hexavalent and two pentavalents, respectively. The multiple aneuploid tetraploid showed very vigorous growth and varying frequencies of hexavalents and pentavalents. All the five aneuploids showed high Anaphase-I anomalies; pollen sterility ranged from 50% to 81%.Financial assistance of C.S.I.R., New Delhi, India is acknowledged.