Thirty-five Taiwania cryptomerioides Hay. clones in a Tsuyunshan seed orchard established in 1981 in the central part of Taiwan were observed for production of cones in 1999, 18 yr after field planting. Clones were divided into 4 populations and analyzed for 3 yr for growth and production of cones and filled seeds. Most variations (p<0.001) in height and diameter at breast height (dbh) per graft were due to differences between populations and between clones within a population. The best population for height and dbh growth was from Tasheueshan and the worst population was from Guanshan. Most variations in the numbers of cones per graft and filled seeds per cone were due to differences between clones. In 2001, 20 yr after field planting, 31 clones and 38% of grafts had cone production, but they produced no filled seeds. In 2002, 25 clones and 20.4% of grafts produced cones, but only clone no.31 had filled seeds, and the average number of filled seeds per cone was 0.01. In 2003, 28 clones and 32.9% of grafts had cone production, 43.6% of these grafts with filled with seeds, and the average number of filled seeds per cone ranged from 0.01 to 1.7. Germination rates of filled seeds per cone varied from 0 to 100%, but 83.9% of them were 100%. Artificially increasing pollen supply (by supplemental mass pollination (SMP)) was directly applied to receptive seed cones to increase seed yields. The success rates was 80%. The results indicated that the major loss of seeds resulted from insufficient pollen in the ovules.
Thirty-five Taiwania cryptomerioides Hay. clones in a Tsuyunshan seed orchard established in 1981 in the central part of Taiwan were observed for production of cones in 1999, 18 yr after field planting. Clones were divided into 4 populations and analyzed for 3 yr for growth and production of cones and filled seeds. Most variations (p<0.001) in height and diameter at breast height (dbh) per graft were due to differences between populations and between clones within a population. The best population for height and dbh growth was from Tasheueshan and the worst population was from Guanshan. Most variations in the numbers of cones per graft and filled seeds per cone were due to differences between clones. In 2001, 20 yr after field planting, 31 clones and 38% of grafts had cone production, but they produced no filled seeds. In 2002, 25 clones and 20.4% of grafts produced cones, but only clone no.31 had filled seeds, and the average number of filled seeds per cone was 0.01. In 2003, 28 clones and 32.9% of grafts had cone production, 43.6% of these grafts with filled with seeds, and the average number of filled seeds per cone ranged from 0.01 to 1.7. Germination rates of filled seeds per cone varied from 0 to 100%, but 83.9% of them were 100%. Artificially increasing pollen supply (by supplemental mass pollination (SMP)) was directly applied to receptive seed cones to increase seed yields. The success rates was 80%. The results indicated that the major loss of seeds resulted from insufficient pollen in the ovules.