Objective:

2

To study the quality grading standards of

Rheum palmatum

seedlings.

Method:

2

The quality indicators

such as fresh weight

root length

root diameter

number of lateral roots and seedling lesions

of 80

R

.

palmatum

seedlings from different producing areas in Gansu Provincial Real Estate District were detected

and the K-mean cluster analysis results of each data were used as reference basis for dividing the seedling quality level.

Result:

2

The fresh leaf weight

root length and root diameter were used as the main grading indicators to classify the rhubarb seedlings into four grades. Specifically

the extra-large seedlings have a plant weight >30.0 g

the root diameter>2.3 cm

and the root length >30.0 cm

with lateral roots

buds intact

no lesion

wounds. The first grade seedlings have a plant weight ≥25.0 g

root diameter≥2.1 cm

root length ≥25.0 cm

with no lateral root of more than 3 mm in diameter

bud intact

disease-free spots and wounds. The second grade seedlings have a plant weight ≥20.0 g

roots ≥1.8 cm

root length ≥20.0 cm

with no lateral roots with a basal diameter of more than 4 mm

complete buds

no lesion

wounds. The third grade seedlings have a plant weight ≥15.0 g

root thickness ≥1.5 cm

root length ≥15.0 cm

with a few lateral roots

intact buds

no lesion

wounds.

Conclusion:

2

Among the 80 samples of

R

.

palmatum

seedlings collected

the second and third grade seedlings accounted for 68.8%. The different grades of

R

.

palmatum

seedlings were transplanted as herbs after field processing. In terms of the fresh yield

the first grade

>

extra-large seedling

>

the second grade

>

the third grade seedlings

and in the plant twitch rate

extra-large seedlings

>

the first grade

>

the second grade

>

the third grade seedlings. Therefore

the first and second seedlings are recommended standardized production

rather than extra-large seedlings.