黄瓜单性结实产量组成的遗传相关和通径分析

Genetic Correlation and Path Coefficient Analyses of Parthenocarpic Yield Components of Cucumber

选用７个雌雄同株的黄瓜品种，研究雌花数、单性结实果数、平均单性结实果重和单性结实产量等４种性状的遗传相关和通径系数。结果表明：雌花数与单性结实果数、单性结实产量之间以及单性结实产量与单性结实果数、平均单果重之间均呈极显著正相关，遗传相关系数分别为０．８３８、０．６８０、０．９２５和０．６１２。而雌花数、单性结实果数与平均单性结实果重之间的相关未达显著水平。因此，黄瓜单性结实性能可以通过选择其雌性表现而进行间接选择。但由于雌花数对产量的直接作用（直接通径系数０．１４１）远小于它通过单性结实果数对产量的间接作用（间接通径系数为０．５６４），因而，选种实践中，在考察品种雌性表现是否优良的同时，应着重考察其雌花的单性结实能力。）ａｎｄｗｉｔｈＰＹ（ｒ＝０．６８０）；ＰＹｓｈｏｗｅｄｐｏｓｉｔｉｖｅｇｅｎｅｔｉｃｃｏｒｒｅｌａｉｏｎｓｗｉｔｈＮＰＦｒ（ｒ＝０．９２５）ａｎｄｗｉｔｈＳＦＷ（ｒ＝０．６１２）．ＮｏｓｉｇｎｉｆｉｃａｎｔｇｅｎｅｔｉｃｃｏｒｒｅｌａｔｉｏｎｗａｓｆｏｕｎｄｂｅｔｗｅｅｎＮＰＦ１ａｎｄＳＦＷａｎｄｂｅｔｗｅｅｎＮＰＦｒａｎｄＳＦＷ．Ｔｈｕｓ，ｉｔｍｉｇｈｔｂｅｐｏｓｓｉｂｌｅｔｏｓｅｌｅｃｔ?

Genetic correlation and path coefficient analyses of four characters──number of pistillate flowers (NPF1), number of parthenocarpic fruits (NPFr), average single fruit weight (SFW) and parthenocarpic yield (PY), were studied with 7 monoecious cultivars of cucumber (Cucumis sativus L.). The results indicate that NPF1 showed positive genetic correlations with NPFr (r=0.838**) and with PY (r=0.680**); PY showed positive genetic correlaions with NPFr (r=0. 925**) and with SFW (r=0. 612**). No significant genetic correlation was found between NPF1 and SFW and between NPFr and SFW. Thus, it might be possible to select for partheno carpie ftuiting ability through indirect selection according to pistillate performance. However, the direct effect of NPF1 on PY (path coefficient 0. 141) was far less than its indirect effect through NPEr (path coefficient 0. 564).Therefore, in cucumber breeding, it is necessary to pay special at tention to parthenocarpic fruiting ability while examining pistillate performance.