소맥(小麥) $F_2$집단(集團)에 있어서 조숙(早熟) 다수성(多收性) 계통(系統)의 효율적(效率的)인 선발(選拔)에 관(關)한 기초자료(基礎資料)를 얻고자 중숙(中熟)${ imes}$조숙(早熟)(올밀/새밀), 만숙${ imes}$중숙(中熟)(Naphal/청계밀) 두 조합(組合)을 공시(供試)하여 $F_2$집단(集團)의 유전적(遺傳的) 변이(變異)를 조사(調査)하고 경로분석(徑路分析)을 한바 얻어진 결과(結果)는 다음과 같다. 유전변이계수(遺傳變異係數)는 올밀${ imes}$새밀 조합(組合)에서는 수획지수(收獲指數), 립수(粒數), 수량(收量), 간장(稈長)의 순(順)으로, Naphal${ imes}$청계밀 조합(組合)에서는 수획지수(收獲指數), 간장(稈長), 1,000 립중(粒重)의 순(順)으로 높았다. 유전력(遺傳力)(협의(狹意))은 양조합(兩組合)에서 출수기(出穗期), 성숙기(成熟期), 간장(稈長), 수획지수(收獲指數)가 높았고(0.525~0.808) 립수(粒數), 수량(收量)은 낮았다. 유전획득량(遺傳獲得量)(%)은 출수기(出穗期), 성숙기(成熟期)가 양조합(兩組合)에서 모두 높았고 수량(收量)은 낮았다. 1,000립중(粒重)의 유전획득량(遺傳獲得量)(%)은 Naphal${ imes}$청계밀 조합(組合)에서는 높게 나타났다. 수량(收量)과 수수(穗數) 및 립수(粒數)와는 높은 정(正)의 유의상관(有意相關)을 보였고 수량(收量)에 대(對)한 직접효과(直接效果)는 수수(穗數)가 가장 컸고 다음은 립수(粒數)였다.
This study was conducted to obtain the basic informations on the selection for the early and high-yielding lines in $F_2$ populations of wheat. Two combinations such as Olmil-Saemil cross and Naphal-Cheonggemil cross and their eight populations were used and genetic parameters of genetic variances and path-coefficients for agronomic traits mainly in $F_2$ populations were analyzed. Genetic coefficient of variability in Olmil-Saemil cross was higher in harvest index, grain number, grain yield and plant height in decreasing order, but in Naphal-Cheonggemil cross harvest index, plant height, and 1,000-grain weight were higher in order. Heading and maturing dates, plant height, and harvest index showed high hertability (0.525-0.808) in both crosses, but very low heritabilities were observed in grain numbers per panicle and yield. In both crosses, genetic advances(%) was higher in heading and maturing stage, but lowest in yield. High genetic advance was obtained in 1,000-grain weight of Naphal-Cheonggemil cross. The highly significant correlations between yield and panicle number, yield and grain number per panicle were obtained, and the highest direct effect on yield was obtained in panicle number followed by grain number per panicle number.
