Opisthopappus Taihangensis Research Articles

First intergeneric hybrids within the tribe Anthemideae Cass. III. Chrysanthemum indicum L. Des Moul. × Opisthopappus taihangensis (Ling) Shih

Ovule rescue was used to obtain the intergeneric hybrid Chrysanthemum indicum L. Des Moul. x Opisthopappus taihangensis (Ling) Shih. The hybridity of the seven independent progeny was confirmed by morphology, chromosome counting and GISH analysis. Plant height, crown width, leaf length, leaf width, epidermal hair height and epidermal hair length of the hybrid were all intermediate between those of the parents. However, their petiole length and epidermal hair density exceeded those of either parent. GISH analysis of the hybrid was able to distinguish between the parental genomes.

五种高速公路边坡绿化植物的生理特性及抗旱性综合评价

A test of potting methods used to control soil water was applied to study the physiological characteristics and drought resistance of five plants used for highway shoulder greening and ecological restoration in northern China.Leaf water potential,photosynthesis parameters and fluorescence parameters of five plants were measured under four levels of water stress.The drought resistance of the plants was evaluated to study the average rate of change in various parameters. The results show:(1) as water stress increased,leaf water potential(ΨL),net photosynthesis(Pn),transpiration(Tr),and stomatal conductance(GS) of the five plants gradually decreased;as water stress increased,water use efficiency(WUE) of the five plants first increased and then decreased but the internal CO2(Ci) of the five plants first decreased and then increased.There were some differences in the changing amplitudes and inflection points of the physiological indices.Sedum spectabile and Iris lactea var.chinensis had relatively small average rates of change,while Opisthopappus taihangensis and Saponaria officinalis had relatively large average rates of change.(2) The Ci of S.spectabile and I.lactea var.chinensis reached a minimum value under moderate water stress(W2),while the Ci of Parthenocissus quinquefolia,O.taihangensis and S.officinalis reached a minimum value under mild water stress(W1).Changes in Gs and Ci under water stress were reflected in changes in Pn;the decrease in Pn observed in S.spectabile and I.lactea var.chinensis were mainly caused by stomatal limitation resulting from the change from a normal water supply(CK) to moderate water stress(W2),while non-stomatal factors caused the changes observed under severe water stress(W3).The decrease in Pn in P.quinquefolia,O.taihangensis and S.officinalis was mainly caused by stomatal limitation under normal water supply conditions(CK) and mild water stress(W1),and by non-stomatal factors under moderate water stress(W2) and severe water stress(W3).WUE of S.spectabile and I.lactea var.chinensis had the highest under moderate water stress.WUE of P.quinquefolia,O.taihangensis and S.officinalis had the highest under mild water stress.(3) As water stress increased,initial inflorescence(Fv),maximum inflorescence(Fm),the ratio of variable to maximum(Fv/Fm),or initial inflorescence(Fv/Fo) of the five plants decreased gradually and Fo of the five plants increased gradually.This indicated the energy of PSII was transformed into a reduction in photochemical energy and additional energy was lost as heat and through fluorescence,which led to reduced photosynthesis.(4) The drought resistance of the five plants was evaluated by principal component analysis based on the average rate of change of each plant under water stress.The comprehensive drought evaluation indices of S.spectabile and S.officinalis/O.taihangensis were the highest(0.898) and lowest(0.125),respectively.The drought resistance order follows: S.spectabile I.lactea var.chinensis P.quinquefolia O.taihangensis S.officinalis.The results of cluster analysis shows S.spectabile and I.lactea var.chinensis were the most drought resistant plants,P.quinquefolia exhibited a medium level of drought resistance,and O.taihangensis and S.officinalis had poor drought resistance.

Intergeneric hybridizations between Opisthopappus taihangensis and Chrysanthemum lavandulifolium

For the first time, reciprocal intergeneric hybridizations were produced between Opisthopappus taihangensis and Chrysanthemum lavandulifolium without emasculation. About 20% seed set was similarly obtained from reciprocal hybridization. Only 5 and 6 of the viable plants observed from 45 and 78 seedling survived present some conspicuous intermediate characteristics. Phenotypic evaluation among the progenies of the parents and the putative hybrids was performed carefully since an average of 5.3% seed set was produced in the type of self-pollination using pollen from the same flower and >10% seed set was similarly obtained in the types of self-pollination using pollen from different flowers in a plant and flowers in individual plants from different seeds. One individual of each hybrid shared the inflorescence habit with the pollen plant was confirmed further by the sequence of ncpGS. The two hybrids might be used as bridges of breeding of multi-generic hybrids.

Reproductive characteristics of Opisthopappus taihangensis (Ling) Shih, an endangered Asteraceae species endemic to China

Opisthopappus taihangensis is an endangered species endemic to China and represents an important genetic resource for chrysanthemum improvement. We describe here its basic reproductive characteristics. The anthers are tetrasporangiate and the anther wall is composed of an epidermis, endothecium, middle layer and tapetum. The middle layer is lost by the microspore tetrad stage, and the tapetum disintegrates at the trinucleate pollen stage. Meiosis in the microspore mother cells is of the simultaneous type, and the tetrad is tetrahedral in shape. Mature pollen grains have three germinal apertures, two sperm nuclei and one vegetative nucleus. The in vitro pollen germination rate is only ∼10%. The ovule is anatropous, dual-integument, tenuinucellatae and the development of the embryo sac follows the Oenothera pattern. The archesporial cell below the nucellus epidermis functions as the megaspore mother cell and forms a linear tetrad. The embryo passes through a globular, heart and torpedo stage before maturing into a cotyledon embryo. The endangerment of O. taihangensis may be associated with low reproductive capacity, as a consequence of poor pollen viability.

Karyotype and meiotic analyses of six species in the subtribe Chrysantheminae

The karyotypes and meiotic behaviour of six Chrysantheminae species are investigated. Pyrethrum coccineum (Willd.) Worosch. is a tetraploid, while the other five species (Argyranthemum frutescens (L.) Sch.-Bip., Opisthopappus taihangensis (Ling) shih, Crossostephium chinense (L.) Makino, Tanacetum vulgare L. and P. parthenium (L.) Sm.) are all diploids. Their karyotypes consist mainly of median centromere and submedian centromere chromosomes, although C. chinense also has two terminal centromere chromosomes, and P. parthenium two subterminal centromere chromosomes. No satellited chromosomes are observed in any of the six species. All the species have a 2A type karyotype, except for P. coccineum which is 3A. The meiotic behaviour in the pollen mother cells (PMCs) of all six species is essentially normal, with metaphase I chromosome pairing configurations in the diploid species predominantly showing 9II, while P. coccineum shows 18II. A low frequency of quadrivalents (and trivalents) and chromosome bridges/lagging chromosomes is observed.