Reciprocal difference of interspecific hybridization between three different colours of Iris dichotoma and I. domestica

ABSTRACT

Previously, we found that reciprocal F₁ hybrids of purple-flowered Iris dichotoma and I. domestica were different. To further characterize this reciprocal difference, we carried out reciprocal crosses between three different colours of I. dichotoma and I. domestica. Morphological and cytological characters of F₁ hybrids of six interspecific crosses between three different colours of I. dichotoma and I. domestica (three direct and their three reciprocals) were evaluated. The results showed that the fruit-setting rates of three different colours of I. dichotoma as female and I. domestica as male were lower than reciprocal cross combinations, but their seed germination rates were significantly higher than reciprocal ones. Reciprocal differences of F₁ hybrids were observed for most morphological characters. The F₁ hybrids of three different colours of I. dichotoma as female were totally different from their parents; however, the F₁ hybrids of I. domestica as female were extremely similar to the mother. The six interspecific hybrids had the same chromosome number (2n = 32) as their parents. Reciprocal differences were detected for karyotype. Parents’ and F₁ hybrids’ karyotypes focused on 1A to 2B. In these cases, the direction of the cross must be kept in mind in order to improve the efficacy of future breeding programmes.

KEYWORDS:

• Iris
• hybrid
• interspecific hybridization
• reciprocal difference
• karyotype

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Shanghai Landscaping and City Administration Bureau [grant number F122424] and Educational Department of Liaoning Province [grant number L2010491].