Abstract:
Standards for grading seedlings of
Anoectochilus roxburghii (Wall.) Lindl. were studied. Factors includingplant height and weight, average length, width and count of leaves, stem diameter, andinternode countof a seedlingpropagated from tissues were analyzes on their interrelations and chemical compositions to select agrading system.Cluster and statisticalanalyses were performed to weigh those factors against the survival rate of the seedlings. The results indicated that the plant height and weight, as well as the stem diameter were the determining indicators for an effective grading. Three classifications were thus established:the 1
st Grade to show a seedling height of ≥ 130 mm, a stem diameter of ≥ 2.8 mm, and a weight of ≥ 1.3 g; the 2
nd Grade, a seedling height of ≥ 110 mm, a stem diameter of ≥ 2.4 mm, and a weight of ≥ 1.0 g; and, the 3
rd Grade, a seedling height of ≥ 90 mm, a stem diameter of ≥ 2.1 mm, and a weight of ≥ 0.6 g.The proposed standards would allow a clearly definedevaluation on seedings in the breeding practices.