| Summary: | 碩士 === 國立中興大學 === 農業經濟學系研究所 === 84 === Exploration of the genetic diversity among peanut (Arachis hypogaeaL.) var
ieties should be helpful to peanut breeders. Using pedigree analysis,twenty pe
anut varieties released in Taiwan were examined to determinerelative genetic c
ontribution (RGC) from ancestral varieties or lines andcoefficient of parentag
e (r) for all pairwise fo peanut varieties. Thepedigrees of the peanut varieti
es were traced to ten ancestors. PeikangWhite Oil Bean, the Taiwan land race,
contributed the major portion (34.7％) of the genetic base in these varieties,
and three ancestors(PeikangWhite Oil Bean, Spanish White and Florispan Runner
) comprised 62.2％of the total genetic base. The average r value between varie
ties or lines is0.057. The r value between Tainan 12 is 0.008. These varieties
wereseparated into three clusters by using cluster analysis based on r matrix
.Peanut varieties or lines contained in the first and the third cluster wereal
l found in all pedigrees of peanut varieties released from TainanDistrict Agri
cultural lmprovement Station. The second cluster included eightvarieties or li
nes such as Tainung 4,5 and 6,etc. The others includingTainan White Oil Bean 2
, 5 and Tainung 1, etc. were all selected frompure line selection. Furthermoe
, the differences of crop genomes were directly detected byRAPD in DNA level.
It Was found that, the mean genetic distance was0.411 among varieties, and var
ieties were classified into 5 groups:the firstgroup include Tainung 1,2 and th
e other 21 Varieties; the second grouponly had Tainan 7; the third grop had PI
314817 and Chiba Bunch; thefourth group had Ponghu 2 and Java 2 ; the last gr
oup included Tainung 5,which had the farthest genetic distance away from the o
ther varieties.Peikang White Oil Bean, Spanish White, and Florispan Runner had
accumulated genetic contribution was 62.2％,but the genetic distance was0.378.
Genetic base of Taiwan peanut varieties can be broadened by usingcrosses betw
een low relationship genotypes. In order to broadenpeanut genetic diversity ,
the varieties have closer parental relationshipshould not be chosen as hybrid
parents in peanut breeding program.The geneticdistance is smaller among the va
rieties released from Tainan District Agricul-tural Improvement Station. It me
ans that the genetic componets are very close,so it should be cautious that th
e loss in culture when these varieties face the stress.
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