Manila, The Philippines
March 8, 2007
By Sosimo Ma. Pablico,
The Philippine STAR via
SEAMEO SEARCA
The national Rice Technical
Working Group (RTWG) has recommended seven promising rice lines
to be released by the National Seed Industry Council (NSIC) as
commercial varieties.
Agriculture Secretary Arthur C. Yap, who is also the NSIC
chairman, is expected to approve the release of the new
varieties soon.
Still in their coded names, the new promising lines are PR27843,
IR71137, PR30138, PR31561, C6824, IR77186, and PR30536.
Researchers involved in the Rice Varietal Improve-ment Group
(RVIG) and PhilRice were credited for the development of the
seven lines.
Except IR71137 which is recommended only for transplanted
condition, the other six lines have been found to produce good
yields both in transplanted and direct wet-seeded conditions.
The amylose content of PR30138 is high, while that of PR30536 is
low. The rest have intermediate amylose content. All of them,
however, are early maturing.
PR27843 is a cross between PR26668-29-2 and Burdagol, a
high yielding line with intermediate resistance to tungro.
PhilRice consulting plant breeder Hilario dela Cruz said
PR26668-29-2 is a product of the JICA-PhilRice second technical
cooperation project.
Results of trials showed that the yield of PR27843 was 24.3
percent higher than PSB Rc28 during the wet season and 9.8
percent higher across four seasons over the same variety in the
National Cooperative Tests (NCT) 1. It also produced a positive
yield advantage of 6.3 to 7.1 percent in the multi-adaptation
trials (MAT), both under transplanted and direct wet seeded rice
conditions.
It has intermediate reactions to blast, bacterial leaf blight,
sheath blight and white stemborer and is also resistant to
yellow stemborer.
IR71137 has long and slender grains, intermediate amylose
content, and high milling and headrice recoveries. Its yield is
14.2 percent higher than that of IR841. It has intermediate
reactions to blast, bacterial leaf blight, sheath blight, white
stemborer, green leafhopper, and brown planthopper.
PR30138 yielded 7.5 percent higher than PSB Rc18 in the
MAT under transplanted con-dition. Under direct wet seeded
condition, its yield was an average 8.7 percent higher than PSB
Rc18 in both seasons; it even rose to 15.8 percent higher in the
dry season. It is moderate-ly resistant to whitehead caused by
yellow stemborer and has intermediate reactions to blast,
bacterial leaf blight, white stemborer, green leafhopper, and
yellow stemborer.
PR3561 is the country's second product of biotechno-logy that
will be released as a variety. Dela Cruz said this line is an
improved PSB Rc14 with the incorporation of bacterial leaf
blight resistance from IRBB5-21 through marker-aided selection.
Its yield under transplanted condition during the wet season in
NCT 1 was 21.4 percent higher than PSB Rc28. Under direct wet
seeded condition in the wet season, however, its yield was only
9.1 percent higher than PSB Rc28. In the MAT, its yield was an
average 6 percent higher than PSB Rc28 across seasons.
It is moderately resistant to whiteheads caused by yellow
stemborer. Likewise, it has intermediate reactions to bacterial
leaf blight, white stemborer, green leafhopper, yellow
stemborer, and brown planthopper.
C6824 showed superior performance in NCT 1 during the dry
season: 7,191 kg/ha as transplanted crop and 7,104 kg/ha as
direct wet seeded crop. These yield levels were 10 percent and
5.4 percent higher than PSBRc18 under transplanted and direct
wet seeded conditions, respectively.
In the MAT, it yielded higher than PSB Rc82 during the dry
season by 5.1 percent as transplanted rice and 9.9 percent as
direct wet seeded rice. It is resistant to whitehead caused by
yellow stemborer and has intermediate reactions to white
stemborer, yellow stemborer and brown planthopper.
In five NCT 1 seasons, IR77186 yielded an average 7,036
kg/ha as transplanted rice and 7,115 kg/ha as direct wet seeded
rice. During the wet season, its yield as transplanted rice was
12.4 percent higher than PSB Rc28 but their yields as direct wet
seeded rice were almost similar. In the MAT, IR77186 yielded
5,983 kg/ha, 7.4 percent than PSB Rc82.
It is resistant to deadhearts and moderately resistant to
whiteheads caused by white stemborer. It has intermediate
reactions to blast, bacterial leaf blight, sheath blight,
modified rice tungro virus, and green leafhopper.
The yield of PR30536 is comparable with PSB Rc18 across
seasons in NCT 1, but its average yield as direct wet seeded
rice (6,747 kg/ha) was higher than as transplanted rice (6,427
kg/ha). Its MAT dry season yield was 12.7 percent higher than
that of PSB Rc82.
It is resistant to whiteheads caused by yellow stemborer and
moderately resistant to whiteheads caused by white stemborer.
Likewise, it has intermediate reactions to blast, bacterial leaf
blight, and green leafhopper. It has low amylose content and,
hence, it is sticky or cohesive, tender and smooth like japonica
rice when cooked. |
|
