Cheng's Index

Hi! Is anyone familiar with Cheng’s Index for differentiating indica type rice from japonica? I have read some publications but they don’t say much. There are six characters to be measured or scored for the index computation namely, glume hair, leaf hair, glume color at heading stage, grain length-width ratio, length of the first to second rachis internode, and phenol reaction. However,I don't know the specific protocols for each trait. Cheng's paper is in Chinese.

Cheng K S. 1993. Indentificating of Subspecies of Indica and
Japonica in Oryza sativa L. Science Publishing House of
Yunnan, Kunming. 

Where can I find a detailed protocol for the measurements necessary and the computation? Thank you!

Maoqing Wang

glume hair:0(short, orderly ,hard, straight, uniform); 1(hard, a little bit of orderly, longish); 2(middle long, a little bit of disorderly a little bit of soft or verrucous enation); 3(long,  a little bit of soft, disorderly); 4(long, rough-and-tumble, soft)

phenol reaction:0(black); 1(grey black or black brown); 2(gray); 3(micro-colour reaction  on the border); 4(no colour reaction)

length of the first to second rachis internode:0(< 2 cm); 1(2.1-2.5 cm); 2(2.6-3 cm); 3(3.1-3.5 cm); 4(>3.5 cm)

glume color at heading stage:0(white with a little bit of green); 1(green with a little bit of white); 2(olivine); 3(laurel-green); 4(green)

leaf hair:0(too many); 1(many); 2(medium); 3(few); 4(nought)

grain length-width ratio:0(>3.5); 1(3.5-3.1); 2(3.0-2.6); 3(2.5-2.1); 4(<2)

The sum of the scores of six characters:

 0-8 (H)  

 9-13(H")

14-17(K")

18-24(K)

notes:H(hsien); H"(hsien-cline); K"(keng-cline);K(keng); hsien(indica); keng(japanica)

 

 

posted on March 11, 2013 9:32PM
Maoqing Wang

Cultivars are calssifed into four groups as Hsien(H), Hsien-cline(H”), Keng-cline(K”) and Keng(K) by “morphological index”.The “morphological index” is based on the sum of scores of six characters as follows:.

glume hair0(short, orderly ,hard,straight, uniform); 1(hard, a little bit of orderly, longish);2(middle long, a little of bit of disorderly,a little bit of soft or verrucous enation);3(long,,a little bit of soft, disorderly);4(long, rough-and-tumble, soft)

phenol reaction0(black);1(grey black or black brown);2(gray);3(micro-colour reaction on the border);4(no colour reaction)

length of the first to second rachis internode0(< 2 cm);1(2.1-2.5 cm);2(2.6-3 cm);3(3.1-3.5 cm);4(>3.5 cm)

glume color at heading stage0(white with a little bit of green);1(green with a little bit of white);2(olivine);3(aurel-green);4(green)

leaf hair0(too many);1(many);2(medium);3(few);4(nought)

grain length-width ratio0(>3.5);1(3.5-3.1);2(3.0-2.6);3(2.5-2.1);4(<2)

The sum of scores of six characters: 0-8(H) ; 9-13(H”); 14-17(K”);18-24(K)

Notes: Hsien:indica ; Keng:japanica

posted on March 11, 2013 9:34PM
Arnel Pocsedio

Thank you very much for your response! This will be very helpful.

posted on March 11, 2013 11:42PM
Maoqing Wang

The “morphological index” is Cheng's Index.

posted on March 12, 2013 3:35AM
Maoqing Wang

If you have any question, contact me without any hesitation.

 

posted on March 12, 2013 3:26AM
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