Postharvest quality and molecular genetic identification of isopentenyl tansferase（ipt gene）transgenic lines in Broccoli

• Main Authors: Kuo-Chun Liao, 廖國鈞
• Other Authors: Ming-Che Wen
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/41424875547633976767

碩士 === 東海大學 === 食品科學系 === 91 === Abstract Two major research interests were focused in this study. The first part was on the evaluation of postharvest quality in transgenic (ipt) and non-transgenic lines. The other was the molecular identification of transgene and transgene sergregation in the transgenic (ipt) progeny. The purpose of the first part was to investigate the qualities of ipt-transgenic broccoli. The broccoli varieties or lines included: 90-106、90-118、90-121、90-125 and Green King F1 (donor). Lines 90-106 and 90-118 contained the ipt gene, however in line 90-121 the ipt gene has lost. Line 90-125 was the selfed-pollinated T3 progeny of the Green King. There was no significant difference on moisture content，ash，crude fat and soluble solid content among tested lines. The protein content （3.79％）, soluble solids（8.3 °Brix）, and vitamin A content （82.4 mg/％）of Line 90-125 was the highest. For Line 90-106, the titratable acidity content of the Line 90-106 and Green King F1 were the highest（0.35％）. There was no significant difference on vitamin B1 and B2 among lines. The L-ascorbic acid content （100 mg/％） of Line 90-106 and Green King F1 were the highest. The sodium content （8.26 mg/％） and potassium content （208.36 mg/％） of the Green King F1 was the highest. The calcium content of Line 90-121 was the highest (6.15mg/％) while the magnesium content （13.24 mg/％）of Line 90-118 was the highest. There was no significant difference on iron content among broccoli lines. In respect of floret, the lightness (L*) 、redness (a*)、 yellowness (b*) and the Chroma of the floret of Line 90-125 broccoli was higher than those of the transgenic broccoli, but hue angle of the floret among different lines was not significantly different. The needle tset value of Line 90-106 was the highest （350 g） and blade tset value in the Green King was the highest (4.56 kg). For the second part, selfed-pollinated T3、T4 progeny of ipt transformation lines were used to evaluate the ipt and nptⅡ transgene segregation. Genetic segregation on these T3、T4 lines was screened via PCR identification. From a total of 40 transformed T3 and T4 lines, it was found that there were six segregation patterns between the ipt transgene and nptⅡ reporter gene . Type Ⅰwas characterized as homozygous line with non-segregation for both ipt and nptⅡ gene and 11 transformed liens were included. Type Ⅱ involved 7 lines with both genes segregation for 3:1 ratio. Type Ⅲ Showed 3:1 segregation in the ipt gene but no segregation in the nptⅡ gene and 16 lines were included in this category. Two lines belonged to the type Ⅳ with ipt segregation for 3:1 but deviate from 3:1 in nptⅡ. Type Ⅴ included two lines with the ipt deviating from 3:1 segregation and no segregation was observed in nptⅡ. One line was found in Type Ⅵ which indicated a 1:1 segregation for ipt but no segregation for nptⅡ. Southern hybridization demonstrated that most ipt-transformed lines indicated the 2.2~2.4 Kb fragment. Some T3、T4 selfed progeny remained to have the retarding effect on postharvest yellowing of florets in comparison with the control plants.