Performance of Diploids and Induced Autotetraploids ofCatharanthus roseusunder Different Levels of Nitrogen and Plant Spacings

摘要

AbstractTwo bulk experimental strains of induced autotetraploids,‘Purple tetraploid bulk’ (PTB) and ‘White tetraploid bulk’ ofCatharanthus roseuswere evaluated along with the diploid ‘Purple’ variety (PDB) and a diploid pure line selection PS‐3 in four environments consisting of combinations of two levels each of plant spacing and nitrogen at Bangalore and Hyderabad during 1983—84 and in two additional environments at Bangalore during 1984—85. PTB, in general, performed better than PDB at closer plant spacings, especially in the absence of nitrogen application. The highest increase in economic yield (leaf + root yield) over PDB was recorded by PTB with 45 × 30 cm plant spacing and no nitrogen fertilization. The highest economic yield of PTB (obtained with 30 × 30 cm spacing and 100 kg N per ha) was 26 higher than the highest economic yield of PDB. There were no significant differences between PTB and PDB for content of total alkaloids in leaves within all the environments during both years. Strain × environment interactions were significant for content of total alkaloids in roots during 1983—84. During 1984—85, PTB and PDB did not significantly differ from each other for content of