芥菜抗蕪菁嵌紋病毒與同功異構酶伴連之研究

Abstract

以抗蕪菁嵌紋病毒(TuMV)的苗栗芥菜（R型）和感病的新竹、竹北芥菜（S型）進行七種酵素比較分析；三品種間GOT酵素個體間條帶型均一致沒有差異，基酶圖呈單態型。SkDH和PRX在抗病品系(R)與感病品系(S)有一處不一樣的條帶型，而ACP-α-5群有二處相異的條帶型。後裔檢定以抗病品系（苗栗）感病品系（竹北）的雜交F1及F2代族群，分析ACP，PRX和SkDH之變異性，在雜交F1代各個體中三種酵素表現型（F1型）皆很一致，具表現兩親本型的共顯性現象。F2子代在差異區ACP-α-5F、ACP-α-5S、SkDH-1及PRX-1的分離顯示這些異型酶爲單元體，由後裔分析，知四個相異區爲單一因子遺傳；其基因座分別命名爲Acp-α-5F、Acp-α-5S、Skdh-1和Prx-1,可提供作爲遺傳指標。兩參試品系經接種調查F1、F2代之發病情形，並分析病徵與四個酵素基因表現型之關係；F1代大都均呈現抗、耐病性，顯示抗病性有顯性因子參予；F2分離族群病徵分四群：無病徵（抗病）、脈透明化（耐病）、嵌紋病（感病）和嚴重嵌紋狀（嚴重感病），並分析ACP-α，PRX和SkDH的表現型顯示ACP-α-F，ACP-α-S，SsDH-1和抗病性無相關性，而PRX-1之抗病型（R型），出現40%的抗病株和55%的耐病株，初步顯示，PRX-1和抗病性有關。Prx-1和抗病基因有伴連作用。 The inheritance of ACP-α, GOT, PRX and SkDH isozymes between ”Chu-Pei”, ”Shin-Chu” (susceptible of TuMV) and ”Miau-Li” (resistant to TuMV) mustard were analyzed through progeny testing. Monomorphism of GOT phenotype in three mustards were detected. Since ”Chu-Pei” and ”Shin-Chu” have same band pattern of four isozymes, the progeny test only involved two varieties (Miau-Li and Chu-Pei). The F1 from of ACP-α, PRX and SkDH were characterized by the codominance expression of parental types. Two parental types were recovered in F2 population. The segregation of phenotypes fit a 3:1 ration, demonstrating a monofactor inheritance. It is suggested that null allele of PRX-1 was existing in ”Miau-Li” (R type), and that of ACP-α-5S and SkDH-1 in ”Chu-pei” (S type) mustard. Three isozymes are tentatively assigned to be controlled by Acp-α-5F, Acp-α-5S, Prx-1 and Skdh-1 loci respectively. The result to TuMV was evaluated in ”Miau-Li”, ”Chu-Pei” and their progenies by inoculated test and it is relationship with 4 loci were also analysed. Resistance seem to be specified by dominant genes through F1 generation expression. In F2's judged were by divided into 4 groups including symptomless (resistant), vein clearing (tolerant), mosaic (susceptible) and severe mosaic (serious susceptible). Analysis result from phenotypes of 4 isozymes loci indicated the relationship of resistance (or tolerance) with PRX-1 only. More than 95% of PRX-1 ”R type” was detected in F2 population. It is postulated that Prx-1 loci is association TuMV resistant gene, can be used as genetic marker for TuMV reistance.