(45(1):15-25)Evaluation of Agronomic Characteristics for the Introduced Wild Peanut

本研究主要探討自美國農部（USDA）及印度之國際半乾旱熱帶作物研究所（ICRISAT）引進的12種野生落花生，在臺灣環境下的抗病蟲性（以抗銹病及葉斑病為主）及農藝特性，期望藉落花生種間雜交方法將抗病蟲基因及有用的農藝特性導入臺灣之栽培品種，擴大栽培種之遺傳變異的基本資料。 在臺中農試所環境下，經一年以上的觀察評估及病原菌接種結果得知，除四倍體野生種落花生A. monticola以外，其餘11種二倍體野生種均對銹病具有抗性；葉斑病除了A . monticola、 A. stenosperma及A. batizocoi 3種外，其餘9種均具有中度以上的抗性。野生種之生長習性為一年生或以上的匍匐或半匍匐之蔓性莖，分枝最長可達2公尺，植株形態與直立株型的臺灣主要栽培品種有很大差異。籽粒百粒重在 5-17g 之間，明顯小於栽培種的47-68g，且均為單籽粒之莢果，莢喙則明顯較栽培種突出。野生種油分含量達到50％ 以上的有6個，其中A. batizocoi 及A. paraquariensis分別為55.7％及55.9％，蛋白質含量達33％以上的有4個，其中A. cardenasii及A. pusilla均為35.0％，這些野生種之油分及蛋白質含量均較栽培種為高。野生種A. chacoense、A. correntina及A. pusilla的初生子房柄為綠色，其餘9種與栽培種均為紅綠色或暗紅色。莖色、種皮色及葉部形態，在各野生種之間的變異均較栽培種大，尤其小葉形態變異非常大，且除A . batizocoi外，其餘之野生種葉面積明顯小於栽培種。Twelve wild peanuts in three sections of the Arachis were introduced from USDA and ICRISAT for interspecific hybridization to broaden the genetic diversity and to improve the disease resistance for the cultivated peanuts in Taiwan. The preliminary results of pathogen inoculation and agronomic characteristics were summarized as follows: Except for A. monticola (tetraploid), all the tested wild peanuts were resistant to rust (Puccinia arachidis ). Nine of the twelves wild peanuts such as, A. villosa, A. paraquariensis, etc. were at least moderately resistant to leafspot (Cercospora arachidicola and Cercosporidium personatum), however A. stenosperma, A. batizocoi and A. monticola were susceptible. The growth habit of wild peanuts was annual and/or perennial, with procumbent or decumbent vine stems, and the branch crawal up to two meters showed significant different to the cultivars of Taiwan. The 100-seed weight of wild peanuts (5-17g) were less than thoses of the cultivated varieties (47-68g). Pod of the wild species bears only one seed and has prominent beak on the pod. The wild peanuts showed higher oil and protein contents as compared to the cultivate varieties. Six of the twelve wild peanuts contained over 50%, among them A. batizocoi and A. paraquariensis were 55.7% and 55.9%, respectively. Four of the wild peanuts carry more than 33% protein. Pegs of A. chacoense, A. correntina, and A. pusilla were green color, however, the peg color of the other wild peanuts and the cultivated varieties were green with red or dark red. A wide variation was found in stem color, seed coat color, and leaf shape of the wild peanuts, especially the leaflet shape. Except for A. batizocoi, all the wild peanuts showed smaller leaf as compared to the cultivated varieties