ที่มา:วิทยาสารเกษตรศาสตร์ สาขา วิทยาศาสตร์

หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Improved Tryptophan Content in Maize with Opaque-2 gene Using Marker Assisted Selection (MAS) in Backcross and Selfing Generations)

ผู้เขียน:ดร.ชูศักดิ์ จอมพุก, รองศาสตราจารย์, Pachara Cheuchart, ดร.พีรนุช จอมพุก, รองศาสตราจารย์, ดร.สมศักดิ์ อภิสิทธิวาณิช, รองศาสตราจารย์

สื่อสิ่งพิมพ์:pdf

Abstract

The low nutritive value of the maize endosperm protein is genetically controlled. However, quality protein maize (QPM) which is available today contains the opaque-2 gene (o2o2) for double tryptophan content in the endosperm along with numerous modifiers for kernel vitreousness. The objectives of this study were: 1) to convert normal inbred lines to QPM inbred lines by the backcross method and marker-assisted selection (MAS) of the opaque-2 gene and 2) to estimate the combining ability of QPM inbred lines for yield and some agronomic characters. Crosses were made between normal maize and QPM as female and male parents, respectively. These were backcrossed to the recurrent parent. By the marker phi057, it was shown that all F1 were heterozygous (O2o2) while the BC1F1 progenies of Agron20 ? Pop65C6-46 and Agron29 ? Pop65C6-55 had 1:1 ratio of homozygous dominant (O2O2) to heterozygous (O2o2). The heterozygous offspring were self-pollinated to produce the BC1S1. By the marker of phi057 again, homozygous recessive (o2o2) plants were identified in one and six from the crosses of Agron20 ? Pop65C6-46 and Agron29 ? Pop65C6-55, respectively. The protein content in the endosperm of these seven lines ranged from 7.35 to 7.72% and the tryptophan content in the protein ranged from 0.70 to 0.84% which was in the range known for opaque-2 maize (0.80%), twice more than in normal maize (0.41%). The diallel cross of BC1S2 lines was made by Griffing’s Method 4 (fixed effect) and 21 F1-hybrids were obtained. The best test hybrid yielded 7.67 t ha 1, which was close to the commercial single cross hybrid (KSX4452; 8.35 t ha-1). One line (P1) had the best combination of general combining ability effects for grain yield; a second line (P6) was almost equal. Both were considered to be suitable as tester lines for the quality protein maize program.

Article Info

Agriculture and Natural Resources -- formerly Kasetsart Journal (Natural Science), Volume 045, Issue 4, Jul 11 - Aug 11, Page 666 - 674 |  PDF |  Page

ที่มา:วิทยาสารเกษตรศาสตร์ สาขา วิทยาศาสตร์

หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Detection of Quality Protein Maize (QPM) using Simple Sequence Repeat (SSR) Markers and Analysis of Tryptophan Content in Endosperm)

ผู้เขียน:ดร.พีรนุช จอมพุก, รองศาสตราจารย์, ดร.วาสนา วงษ์ใหญ่, รองศาสตราจารย์, ดร.ชบา จำปาทอง, Somsak Apisitvanich

สื่อสิ่งพิมพ์:pdf

Abstract

Quality protein maize (QPM) controlled by opaque-2 (o2) gene was detected using two simple sequence repeat (SSR) markers and further confirmed by tryptophan content in the endosperm. Three populations, i.e., Pop61C1, Pop62C6 and Pop65C6 from the International Maize and Wheat Improvement Center (CIMMYT) were used. S0-plants were selected for the presence of QPM using two markers (phi057 and phi112) as indicated by the amplified products of 140-160 bp. The phi057 marker identified 24 out of 40 Pop61C1 plants (60%), 34 out of 35 Pop62C6 plants (97%) and 24 out of 30 Pop65C6 plants (80%) to be opaque-2 positive while phi112 marker identified 34 (85%), 35 (100%) and 30 (100%) to be opaque-2 plants from the respective populations. Since phi112 was a dominant marker not for detecting the heterozygous genotype, it could only indicate the difference between QPM inbreds and normal maize. The phi057, on the other hand, is a co-dominant marker and could identify the heterozygote of maize plants and therefore, the contamination of non-QPM presented in CIMMYT population. The endosperms of selected S1-seed were further analyzed for the tryptophan and protein content. The three maize populations were found containing the same protein quantity, but different in tryptophan content. The average tryptophan contents in endosperm of QPM and non-QPM as detected by phi057 marker were 0.66% (for QPM), 0.38% (for non-QPM), 0.38% for Suwan 1 (a non-QPM) and 0.80% for the opaque-2 control variety. Moreover, those QPM and non-QPM plants detected by phi112 showed the same result of total protein and tryptophan content in endosperm. To detect heterozygote maize for backcross breeding program, phi057 was considered more feasible than phi112 as a marker assisted selection (MAS) for opaque-2 and to identify QPM line in the short period of time.

Article Info

Agriculture and Natural Resources -- formerly Kasetsart Journal (Natural Science), Volume 040, Issue 3, Jul 06 - Sep 06, Page 768 - 774 |  PDF |  Page