Production and characterisation of the intergeneric hybrids between Dendranthema morifolium and Artemisia vulgaris exhibiting enhanced resistance to chrysanthemum aphid (Macrosiphoniella sanbourni)

Abstract

Aphids represent the most destructive of chrysanthemum pests to cultivation. Reliable variety sources of resistance and control methods are limited, so development of highly resistant breeding lines is desirable. An intergeneric hybrid between Dendranthema morifolium (chrysanthemum) variety 'Zhongshanjingui' and Artemisia vulgaris (mugwort) 'Variegata' was attempted. Most of the hybrid embryos aborted at an early developmental stage. Embryo rescue allowed the generation of hybrid plants, whose hybridity was confirmed by a combination of morphological, cytological and GISH analysis. The hybrids were vigorous, flowered normally, and their flower and leaf shape resembled those of the chrysanthemum more than those of the mugwort parent. The hybrids showed much higher resistance to chrysanthemum aphid (Macrosiphoniella sanbourni) than maternal chrysanthemum by inoculation test. The leaves of the hybrid developed a higher density of trichomes and secretory glands compared to the maternal chrysanthemum. GC-MS analysis revealed that approximately 51% of the essential oil in the hybrid leaves were monoterpenoids and sesquiterpenoids, while the proportion in the chrysanthemum was approximately 37%, and in the mugwort was approximately 90%. It is inferred that higher aphid resistance in the hybrid mainly owed to the leaf micromorphology and bioactive essential oil content.

Salicylic acid-induced changes in physiological parameters and genes of the flavonoid biosynthesis pathway in Artemisia vulgaris and Dendranthema nankingense during aphid feeding

“…The aphid infestation protocol followed the method of Deng et al (2010). Briefly, five 2nd instar aphids were carefully placed on each stem tip of the test plants with a soft brush.…”

“…Artemisia vulgaris (AV) 'Variegata' (mugwort) is an aphid-resistant species due to its leaf morphology and bioactive essential oil content (Deng et al, 2010). Macrosiphoniella sanbourni is a major pest of chrysanthemums, and reduces vegetative growth and flower production and quality.…”

Comparative analysis of genetic diversity among species of Chrysanthemum and its related genera using inter-simple sequence repeat and sequence-related amplified polymorphism markers

“…Fortunately, several studies have shown the cross compatibility between cultivated chrysanthemums and species of Chrysanthemum and related genera (Fukai et al, 2000;Sun et al, 2010b), Thus far, potentially useful F 1 hybrids between cultivated chrysanthemums and species of Chrysanthemum and related genera have been produced through inter-specific or inter-generic hybridization with embryo rescue (Watanabe, 1977;Furuta et al, 2004). Recently, Deng et al (2010Deng et al ( , 2012) transferred resistance to aphid and Alternaria leaf spot from Artemisia vulgaris to cultivated chrysanthemums, and the same authors obtained some F 1 hybrids with enhanced cold tolerance through the hybridization of cultivated chrysanthemum and Ajania przewalskii . Some ornamentally important traits, as well as traits of heat and drought tolerance, were also transferred to chrysanthemum by other authors (Zhao et al, 2007;Sun et al, 2010a;Cheng et al, 2011).…”

“…Moreover, some of the species are endowed with novel traits of horticultural interest and strong stress and disease resistance that are not present in chrysanthemum cultivars (Sun et al, 2010a;Deng et al, 2010Deng et al, , 2011Deng et al, , 2012. Hence, many new cultivars of chrysanthemum with improved target traits possibly will emerge once hybrid parents are expanded to wild species of Chrysanthemum and related genera.…”

Chromosome relationships among the Chrysanthemum fruticulosum complex

“…They may have gene fl ow bridge by introgressive hybridization between the Chrysanthemum fruticulosum complex and Artemisia obtusiloba. Artemisia can be artifi cially hybridized with Chrysanthemum such as Dendranthema (=Chrysanthemum) morifolium X Artemisia vulgaris by Deng et al (2010). …”