Characteristics of Progeny Obtained from the Cross between Geraniums (<b><i>Pelargonium×hortorum</i></b>) and Wild Species in Section <i><b>Ciconium</i></b>, Including Heat Tolerance and Odor of Leaves
In order to develop new geranium cultivars with characteristics not found in existing cultivars, such as heat tolerance and odorless leaves, intercrosses between geranium and four wild species of section <i>Ciconium</i> were carried out. The intercrosses between geranium and <i>P. frutetorum, P. inquinans</i>, and <i>P. salmoneum</i> showed relatively high compatibility, regardless of the seed parent. Their F<sub>1</sub> plants grew vigorously and developed normally. On the contrary, some F<sub>1</sub> plants derived from the intercross with <i>P. acetosum</i> developed chlorosis and variegation in the leaves, with many plants dying in the early stage of growth. However, the F<sub>1</sub> plants that survived showed high pollen fertility, and F<sub>2</sub> and BC<sub>1</sub> generations could be obtained easily. Some F<sub>2</sub> plants showed odorless, and all BC<sub>1</sub> plants had non-trichome leaves. Heat tolerance trial was carried out in a greenhouse from spring to autumn using all plants of F<sub>1</sub>, F<sub>2</sub> and BC<sub>1</sub> obtained from backcrossing to geranium. Favorable plants with an increased number of flowering peduncles even in summer were selected from the BC<sub>1</sub> plants derived from <i>P. frutetorum, P. acetosum</i>, and <i>P. salmoneum</i>. These progeny can be used as breeding material for producing promising new heat-tolerant geraniums with odorless leaves.
- Ｅｎｖｉｒｏｎｍｅｎｔ Ｃｏｎｔｒｏｌ ｉｎ Ｂｉｏｌｏｇｙ
Ｅｎｖｉｒｏｎｍｅｎｔ Ｃｏｎｔｒｏｌ ｉｎ Ｂｉｏｌｏｇｙ 52(1), 37-43, 2014