II.5 Morphology and reproductive characteristics in trisomic 7, semierect.
George Fedak. Ottawa Research Station, C.D.A., Ottawa, Canada.
Plant height, number of spikes per plant and spike fertility of chromosome 7 trisomics (Semierect) from five sources; Shin Ebisu 16, Gateway, O.A.C. 21, H. spontaneum and Betzes were compared to each other and to their disomic sibs. Plants were grown in a growth room at temperatures of 20-15°C, under a 16 hour day, average illumination of approximately 2500 f.c. and relative humidity of approximately 70%. Values for each parameter are stated as averages of six plants.
As shown in Table 1 all trisomics were shorter growing than their corresponding disomic sibs. The shortest trisomic was Gateway at 43.2 cm. and tallest was Betzes at 68.6 cm. Under our growing conditions the largest number of spikes per plant was produced by Semierect of Gateway followed by Betzes with H. spontaneum giving the fewest. Highest spike fertility at 73.3% was observed in Betzes followed closely by H. spontaneum at 71.7%. Lowest spike fertility was recorded in Gateway however this source gave most spikes per plant so its overall reproductive capacity did not differ markedly from other trisomics. When these two factors are considered the reproductive capacities of all trisomics do not vary greatly. The choice of source of trisomic 7 for genetic studies probably will not depend on its reproductive capacity but on availability of material and the particular markers that it inherently carries such as two-row vs. six-row, disease reaction, etc.
Table 1. Plant height, number of spikes and spike fertility of Trisomic 7 from five sources.
