Jr. Schultheis et al., EARLY PLANT-GROWTH AND YIELD OF SWEET-POTATO GROWN FROM SEED, VEGETATIVE CUTTINGS, AND SOMATIC EMBRYOS, Journal of the American Society for Horticultural Science, 119(5), 1994, pp. 1104-1111
Early plant growth, root quality, and yield from sweetpotato plants ob
tained from zygotic seed, somatic embryos, or cloned from stock plants
(through micropropagation, rooted node explants, or nonrooted termina
l vine cuttings) were compared in field plantings established in 1986,
1987, and 1988 in Gainesville and/or Homestead, Fla. At planting, tra
nsplants derived from somatic embryos had more nodes than the other pr
opagules, while vine length per plant was greatest with nonrooted vine
cuttings obtained from stock plants. The number of nodes (up to 253%)
and vine growth (up to 517%) were greater when plants were derived fr
om stock plants and zygotic embryos than from somatic embryos 4 weeks
(1987) and 6 weeks (1988) after planting. Vegetative growth, larger-si
zed storage roots (>6 cm in diameter), and total yields (all root grad
es combined) were consistently. reduced when plants were derived from
somatic embryos compared with propagules of stock plant origin. Plants
obtained from somatic embryos required more time for roots to bulk or
size than the other propagule types. Root yield from plantlets derive
d from somatic embryos showed a 14-fold increase when harvest was dela
yed at least 53 more days. Root weight, regardless of harvest date, wa
s greater when plants were derived from stock plants rather than from
somatic embryos, while in most cases plants derived from somatic embry
os yielded a greater number of roots than from stock plants. Plants ob
tained through somatic embryony and harvested at a later date typicall
y had yields exceed 1.8 kg per plant. Morphology of plants obtained fr
om somatic embryos was uniform and identical to plants derived from st
ock plants.