Leaf Trait Inheritance and Induced-mutation in Coleus

• Main Authors: Ya-Ting Shiu, 許雅婷
• Other Authors: Der-Ming Yeh
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/60288985643480299153

碩士 === 國立臺灣大學 === 園藝暨景觀學系 === 103 === 　　Coleus [Solenostemon scutellariodes (L.) Codd.], with various leaf forms and shapes, are used extensively for landscaping and decoration all year round. Crosses between commercial cultivars and  ray treatments were conducted to have a better understand of leaf characteristics inheritance and induced-breeding in Coleus. Progenies obtained from selfing or crossing cultivars with normal leaf width were all with normal width, except that progeny from selfing ‘Defiance’ resulted in a 3:1 ratio (normal: narrow). These results indicated that characteristic of leaf width was controlled by a single locus, while normal width (W) is dominant to narrow width (w). Progenies obtained from crossing between male-sterile deep lobed and male-fertile deep lobed cultivars resulted in a 3:1 or 1:0 ratio (deep-lobe: shallow-lobe). Progeny from crossing between male-sterile deep lobed and shallow lobed resulted in a 1:1 ratio (deep-lobe: shallow-lobe). Selfing male-fertile deep lobed resulted in a 3:1 ratio, while crossing between male-fertile deep lobed segregated in a 1:1 ratio (deep-lobe: shallow-lobe). These suggested that leaf margin was controlled by a single locus. Deep-lobed and male sterile (L) is dominant to deep-lobed and male-fertile (lF), while the latter is dominant to shallow-lobed and male-sterile (l) .Cultivars with crinkled surface were crossed, and the progeny fit a 3:1 ratio (crinkled: smooth). Crossing between smooth-leaved cultivars produced all smooth-leaved seedlings. Progeny from crossing between crinkled and smooth cultivars fit a 1:0 or 1:1 ratio (crinkled: smooth). These suggested that leaf surface trait was governed by a single locus. Crinkled surface (C) is dominant to smooth surface (c). Crossing between irregular-vein cultivars, between anastomosis and regular-vein cultivars, and between anastomosis cultivars fit a 3:1, 1:1 or 1:0 and 0:1 ratio (anastomosis: regular-vein), respectively in progeny. This indicated that leaf vein trait was governed by a single locus, and anastomosis vein (G) is dominant to regular vein (g). Crossing between purple blotched cultivars and strains resulted in a 3:1 or 1:0 ratio (blotched: non-blotched). Crossing between non-blotched cultivars and strains all had non-blotched progenies. These indicated that purple blotch (B) is dominant to non-blotched leaf (b). Selfing white spotted leaf cultivars resulted in a 3:1 ratio, while crossing white spotted leaf cultivars with non-spotted cultivars resulted in a 1:1 ratio (spotted: non-spotted). These indicated that white spotted trait might be controlled by a single allele, and white spotted leaf (S) is dominant to non- spotted leaf (s). Progenies of crossing between white midrib striped cultivars and midrib non-striped cultivars resulted in a 1:0 ratio. Progenies of crossing between white midrib striped cultivars resulted in a 1:0 or 3:1 ratio. These indicated that white midrib striped trait is controlled by a single allele, and white midrib striped leaf (M) is dominant to midrib non-striped leaf (m). Mesurements were conducted to test net photosynthesis rate under different photosynthetic photon flux in four progenies: ‘Norris’ × ‘Defiance’ - Progeny 08, Fiesta × Wizard Jade 12-11, ‘Norris’ × ‘Defiance’ - Progeny 10 and New Hurricane × Wizard 07. ‘Fiesta’ × ‘Wizard Jade’ - Progeny 11-11 had a highest light saturation and a compansetion point, indicating this strain grew better under sufficient light condition. ‘New Hurricane’ × ‘Wizard Jade’ - Progeny 07 had a similar light compansetion point to ‘Fiesta’ × ‘Wizard Jade’ - Progeny 11-11, but with a lower light saturation point, suggesting it might have a narrow light acclimation range. ‘Norris’ × ‘Defiance’ - Progeny 08 and ‘Norris’ × ‘Defiance’ - Progeny 10 had lower light compansetion points and thus could adapt to lower light condition. ‘Norris’ × ‘Defiance’ - Progeny 10 had the lowest light saturation and compansetion point among the four strain, which means it could grow under low light intensity. 　　The cuttings of ‘Defiance’ and ‘Cardinal’ were treated with  ray. After 6 months, ‘Defiance’ exhibited the lowest survival rate (23%) and highest mutation rate (7.1%) at 25 Gy treatment, while ‘Cardinal’ had the lowest survival rate (66.7%) and highest mutation rate (7.5%) at 50 Gy. Mutation shoots (M0) from ‘Defiance’ were chimeric or yellowish, and ‘Cardinal’ became copper-colored, yellowish, or chimeric. Some of chimeric sports disappeared after propagation with cuttings, indicating that the chimeric phenotype resulted from irradiation damage. Plants with copper-red and yellowish sports remain unchanged after cutting-propagation, and thus had potential to a new germplasm for landscape and commercial uses.