Juliano et al. - 1993 - Grain Quality Evaluation of World Rices
Juliano et al. - 1993 - Grain Quality Evaluation of World Rices
Juliano et al. - 1993 - Grain Quality Evaluation of World Rices
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Oryza glaberrima and other wild rices<br />
Two major cultigens <strong>of</strong> rice are grown in Africa. Oryza glaberrima is<br />
rarely grown in pure stands; instead it is usu<strong>al</strong>ly mixed with O. sativa.<br />
Samples were derived from the IRRI germplasm bank. The IITA gene<br />
bank provided 180 accessions <strong>of</strong> O. glaberrima.<br />
The O. glaberrima samples were <strong>al</strong>l nonwaxy and had predominantly<br />
high AC, low GT, and s<strong>of</strong>t-medium GC (Appendix, Table 9).<br />
The four low-AC rices with 18.9-19.4% AC had 9-12% protein and may<br />
actu<strong>al</strong>ly be intermediate-AC types. Liberia had more intermediate-AC<br />
than high-AC rices. Protein an<strong>al</strong>yses <strong>of</strong> earlier samples were very<br />
limited (Ignacio and <strong>Juliano</strong> 1968). O. glaberrima reflected the distribution<br />
<strong>of</strong> rice starch properties <strong>of</strong> O. sativa in Africa but had less low AC<br />
and hard GC (Table 8).<br />
Protein content correlated significantly with <strong>al</strong>k<strong>al</strong>i spreading v<strong>al</strong>ue<br />
( r = 0.73**, n = 15) and AC ( r = 0.54%). Gel consistency correlated with<br />
<strong>al</strong>k<strong>al</strong>i spreading v<strong>al</strong>ue ( r = –0.24**, n = 179) and AC ( r = 0.18*).<br />
Apparent AC and GT were more evenly distributed in other wild<br />
species than in O. glaberrima (Table 9, 10). All AC types were represented<br />
except very low AC. Intermediate GT predominated; high GT<br />
followed. High GT was prev<strong>al</strong>ent in O. rufipogon, O. nivara, O. breviligulata,<br />
O. latifolia, and O. punctata. Only two high-AC samples <strong>of</strong><br />
O. <strong>of</strong>ficin<strong>al</strong>is had s<strong>of</strong>t GC. Protein content <strong>of</strong> the milled rice from wild<br />
rices was more than that <strong>of</strong> O. sativa, except in O. latifolia.<br />
Amino acid composition <strong>of</strong> the brown rice for wild species was<br />
similar to that <strong>of</strong> cultivated rice (Ignacio and <strong>Juliano</strong> 1968).<br />
Most <strong>of</strong> the 1990 samples were thin-grained. Brown rice 100-grain<br />
wt was less than 1 g. <strong>Grain</strong> length was 2.9-6.3 mm; width was 1.1-2.8<br />
mm. O. ridleyi had a L-W ratio <strong>of</strong> 5.7. It was test tube-milled for <strong>al</strong>k<strong>al</strong>i<br />
spreading v<strong>al</strong>ue.<br />
Among O. breviligulata entries, AC and <strong>al</strong>k<strong>al</strong>i spreading v<strong>al</strong>ue were<br />
correlated ( r = 0.82*, n = 7). Among O. rufipogon entries, AC correlated<br />
significantly with protein content ( r = –0.81**, n = 10) and <strong>al</strong>k<strong>al</strong>i<br />
spreading v<strong>al</strong>ue ( r = 0.92**); the latter correlated with protein content<br />
( r = –0.72**, n = 11).
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