7 new rice lines ready for release as comm’l varieties

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.