 หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Development of Semi-exotic Maize (Zea mays L.) Inbred Lines: Performance per se and in Hybrid Combinations) ผู้เขียน: Putu Darsana,  ดร.กฤษฎา สัมพันธารักษ์, ศาสตราจารย์ , เอนก ศิลปพันธุ์ สื่อสิ่งพิมพ์:pdf AbstractTo create positive transgressive segregation of quantitatively inherited traits such as yield of inbred lines, two or more sources which accumulate different classes of favorable alleles are required. Introgression of exotic germplasm into tropical inbred line is one of several possible methods. This study was conducted to asses a potential use of exotic germplasm introduced from different latitudes to improve tropical inbred lines and their performance in hybrid combinations. The results of the present study indicated that all improved exotic germplasm were equally useful as sources of desirable alleles, especially for high yield of semi-exotic inbred lines. The 25 % semi-exotic inbred lines showed earlier days to anthesis and silking, lower grain moisture content, but higher leaf disease infection than the 12.5 % semi-exotic inbred lines. Transgressive segregation of semi-exotic inbred lines was also found in each class of exotic germplasm. Testcross hybrids generated from crossing between tropical testers with 12.5 % exotic inbred lines showed higher yield, earlier maturity, and better disease resistance than the testcross hybrids of 25 % exotic inbred lines. Result of the present study suggested that combining ability of recurrent parent and the tester as well as proportion of exotic alleles in the converted semi-exotic lines are very importance for a success of semi-exotic inbred lines in hybrid combinations. |
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หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Genetic Potential of Exotic Germplasm Introduced from
Different Latitudes for the Improvement of Tropical Maize
(Zea mays L.)) ผู้เขียน:Putu Darsana, ดร.กฤษฎา สัมพันธารักษ์, ศาสตราจารย์, เอนก ศิลปพันธุ์ สื่อสิ่งพิมพ์:pdf AbstractTo broaden the genetic base of the tropical maize, adding more favorable alleles from exotic
germplasm into the tropical breeding material is one way suggested by plant breeder. For effective
utilization of the exotic germplasm, rapid and efficient method of incorporation of exotic germplasm into
tropical material is needed. This study was conducted to assess a genetic potential and the effectiveness
of exotic germplasm introduced from different latitudes in combination with tropical breeding materials.
The results of the study implied that: semi-exotic populations containing 50 % exotic germplasm showed
the lowest yield, lowest grain moisture content, earliest days to anthesis and silking, highest leaf disease
infection. Semi-exotic populations with 25 % and 12.5 % exotic germplasm showed no significant
difference to population with 0 % exotic germplasm, except semi-exotic population of latitude-2 (> 22.5
– 37.5 ?North Latitude), Southern U.S. germplasm. Significant quadratic response among population
means due to proportion of exotic germplasm was noted for grain yield of the semi-exotic populations
of latitude-1 (> 37.5 ?N.L.), -2, -3 (> 7.5 – 22.5 ?N.L.), and -5 (> 37.5 ?South Latitude). Significant linear
responses were noted for days to anthesis and silking and grain moisture content. Highly significant linear
response to leaf diseases was observed in semi-exotic populations of latitude-1, -2, -3, -4 (> 22.5 –
37.5 ?S.L.), and significant response was shown by exotic source from latitude-5. Population with 50 %
exotic germplasm from latitude-4 “South Africa” was well adapted to tropical condition and showed no
response to the higher degree of tropical germplasm. |
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