Most Hypotetraploid Seedlings from Self-Pollinated Tetraploid Grapes (Vitis complexes) Have Abnormal Cotyledons

To establish a rapid and simple method to determine aneuploidy in seedlings derived from crosses between tetraploid grapes, chromosome number and morphology of cotyledons were examined in the seedlings from self-pollinated two tetraploid grapes, KA9301 and RB9127. Three of 24 seedlings from self-pollinated KA9301 were aneuploid plants with hypotetraploid chromosome number 75 (4x-1), 74 (4x-2) and 73 (4x-3). One of 35 seedlings from self-pollinated RB9127 was also an aneuploid plant with hypotetraploid chromosome number 74 (4x-2). These four aneuploid seedlings showed almost normal growth and leaf morphology, but in three of the four aneuploid seedlings, morphology of cotyledons was highly abnormal. These results suggested the possibility that in crosses between tetraploid grapes most aneuploid seedlings were efficiently selected by their abnormal morphology of cotyledons soon after seed germination.