CARYOLOGIA Vol. 59, no. 4: 345-349, 2006

Ex situ conservation and rare plants propagation in the LecceBotanical Garden: reproductive biology problems

Accogli Rita and Marchiori Silvano

Botanical Garden Sciences and Biological and Environmental Technologies Department, University of Salento -Lecce

Abstract — Among natures conservation strategies, the cultivation ex situ in Botanical Gardens is the more immedi-ate and allows the middle and long term survival of risk extinction and rare species. The conservation of such speciesimposes, first of all, direct observation of principal phases of development in situ and the correct collecting of thepropagation material. Choosing the fitter and faster multiplicative technique surely offers greater opportunities ofconservation ex situ, with elevated phenotypic and genotypic expressiveness populations, and it allows to get an highnumber of individuals to be re-introduced in origin places, with the purpose to strengthen the consistence of thenatural populations and to reduce its vulnerability degree.

Key words: Botanical Garden, conservation, reproductive biology, vegetable biodiversity.

INTRODUCTION

The Lecce Botanical Garden, born only fewyears (1992) as “Center of studies for Mediterra-nean botanical species protection and conserva-tion, with attached botanical garden”, proposes it-self to the public and the scientific world with fi-nality that aims above all to conservation ex situ ofthreatened species, (in captivity propagation) toscientific culture divulging, to environmental re-training projects (Marchiori and Dedej 2000).

The most important goal in a modern Botani-cal Garden is protecting the biodiversity, atten-tively appraising the phyto-geographical contextwhere it is inserted and privileging the flora, par-ticularly that autochtonous and threatened one.With these premises, the Botanical Garden ofLecce shapes him as a modern structure not onlydirected to maintenance, but also to sensitizationand active sharing in programs of recovery andenvironmental safeguard. The principal activitiesof such Institution essentially pursue the follow-ings objectives: territorial biodiversity analysis;propagation material harvest; propagation andcultivation protocols debugging; principal naturalhabitats structuring species multiplication; alivethematic collections coltivation; back-to-natureand restauration interventions in degraded envi-ronments with reintroduction in nature environ-ment of species that characterizes, from the physi-ognomy point of view the principal habitats of

Salento; didactic-divulging activity (Accogli et al.2000).

The Lecce Botanical Garden proposes safe-guard programs which foresee a direct interven-tion in restauration projects of seriously threat-ened or impoverished habitat or environments,through reconstruction or expansion of naturalpopulations; therefore common MediterraneanStain, hinterland principal vegetable associations,coast and wetland typical species are multiplied inspecial collections.

The vegetable species retrieval and harvest ac-tivity allowed to individualize possible bio-geneticreserves on the territory, it motivated studies onphenology and on seeds germinating potentiality,and last but not least, the local eco-types recogni-tion.

Annual species, whose collections are main-tained by renewing every year the seeding, arepicked up and preserved with a simple deposit fora short or middle term maintenance and in aGermplasm Bank for a long-term conservation.

The Botanical Garden therefore represent astudies and monitoring center of the territory ofits pertinence, which effects Nature Conservationprograms, calibrated, according to different localrealities, according to a net that can also interactsto a regional or national level, pursuing a globalsafeguard program.

The retrieved and multiplied vegetable speciesin the Garden represent an ample part of Apuliavegetable biodiversity and they constitute a moth-ers plants reserve from which retrieving materialfor multiplications. The principal alive collectionscoltivated in the Garden are articulated along ademonstrative path:• rare and endemic species collection inserted in

the Regional and/or National Red List andphyto-geographical elevated value species col-lection;

• Catalogue Field of spontaneous species of phar-macological or officinal interest;

• Catalogue Field of wild species ancestors ofthose of agronomic interest;

• Fruit trees species and horticultural species, an-cient local cultivar in extinction danger collec-tion;

• Idrophyte species of handicraft interest (Juncussp.pl., Typha latifolia L., T. angustifolia L.,Phragmites australis (Cav.) Trin.) collection;

• Mediterranean maquis and dunes structuringspecies collection;

• Collection of aromatic spontaneous plants ofgastronomic or industrial interest.Among the alive collections, greater scientific

importance surely assumes that one constitutedby rare and extinction risk species, for which theBotanical Gardens have the institutional assign-ment to adopt opportune maintenance strategies,both in situ that ex situ (IUCN-BGCS & WWF1989).

Particular attention has been turned to thepropagation and maintenance ex situ of the spe-cies distributed on the territory of Apulia and in-cluded in the Red Lists (National and Regional) ofwhich few is still known regarding their ecologicalrole, to their real distribution and reproductive bi-ology.

The few preceding knowledge regarding themultiplication forms of such species motivatedthe attempts of propagation and protocols debug-ging of cultivation, maintenance and managementof alive collections with calendars layout of fruitsharvest (Accogli et al. 1999). In Apulia, theplants exposed to risk are 180 (Conti et al. 1992;Conti et al. 1997). Further updating, gave a re-gional “checklist” that includes 184 “taxa”, ofwhich 19 already extinct in nature and 5 they rep-resent wrong signalings, for which the real contin-gent to be preserved ex situ amounts to 160 spe-cies; which mostly (almost 50%) are distributedon the Gargano, in pedo-climatic conditions diffi-cult to be reproduced in the Botanical Garden ofLecce. The investigations on distribution of sur-

vival risk species, made accessions record ofpropagated material related to 76 species, thatrepresent almost the 48% of the total. The 88%part are represented by “salentine” species, con-firming the garden appointment in the biodiver-sity safeguard of the pertinence territory (Accogli

et al. 2004).

MATERIALS AND METHODS

The propagation material, picked on the terri-tory, consist in: fruits in maturation, seeds, radicaltiller, scions.

The complete maturation of the fruits hasbeen completed in checked environment.

In the receptacle of the capolinis of the com-posite ones, often larvas and parasites developeand damage seriously the fruits (“cipsele”), there-fore their extraction must be effected immediatelyafter the harvest. The same problem occurs formany not dehiscent fruits, which are allowed todry for facilitating the seeds extraction: the larvasthat develope feeding themselves with flower or-gans, jeopardize more seriously fertile seeds pro-duction.

When possible, for the same specie, both thevegetative propagation that generative has beeneffected, using natural or universal substrata, themore possible similar to those of origin habitats.For seeding, scions and transplantations, it hasbeen used PVC containers, maintained in coldtunnel or situated in full field, trying to get the op-timum yield, under water contribution or atmos-pheric agents exposure diversified conditions.Annual repetitions of propagation and germinat-ing seeds tests brought to define, almost for everyspecie, the optimal period of harvest of generativeand vegetative material.

We tried to establish the optimum of propaga-tion yield under not checked conditions and werecorded events that normally occur in nature, asthe competition with infesting species plantule,phytophagous insects preyers (aphids and snails),conditions of water stress (prolonged aridity ordamp) that jeopardize the germinating yield.

RESULTS

The adopted multiplication technical successalso depends by correctly collecting the propaga-tion material you, by the exact knowledge on thespecies biological form (Fig. 1) and as well as bythe harvest timing.

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The geophytes (G) can be propagated both bygenerative or vegetative way. They, in fact, gener-ally produces seeds in abundance, but with verydifferent of germination percentage, according tothe species. For orchids, for instance, a generativepropagation is practically impossible, because ofdifficulties in seeds harvest at the opportune mo-ment and the problems related to germination, of-ten tied up to the presence of micorrhizas.

In general, for the bulbs, the vegetative propa-gation is easier, because of the short bulbs that areproduced at the base of the principal bulbs or in-side the inflorescence from which they detachthemself when they reach such dimensions to beable to conduct autonomous life. This propaga-tion type, even if it is successful, it is rather slowand it doesn’t allow to have mature individuals inbrief times.

Other biological forms (excluded the terofitesthat must be sowed every year), the withdrawnmaterial for vegetative propagation consisted inscions, propagules, tiller, stolons, rhizomes, tufts,in short, portions of plant that contain gems ableto reconstruct new complete individuals with wellformed radical and aerial apparatus.

When seeds or propagules were not available(for instance, for Isoetes histrix Bory, Marsilea stri-gosa Willd., Cheilanthes vellea (Aiton) F.Muell.and all collected Orchidacees) it was necessarytransplantation of the whole plant and the con-tinuation of its reproductive cycle in the Garden(Fig. 2).

For some cases (for instance: Nymphaea albaL. ssp. alba, Ranunculus baudotii Godr, and oth-ers) we proceeded only by vegetative propagation,for of seeds production lacking in the planted out

Fig. 1 — Life form spectrum of the propagated species.

Fig. 2 — Propagative tecnique.

ex situ conservation and rare plants propagation in the lecce botanical garden etc. 347

individuals; instead, the seeds have very oftenbeen so numerous to immediately guarantee alarge number of individuals (for instance: Echi-nops spinosissimus Turra, Prunus webbii (Spach)Vierh., Umbilicus cloranthus Heldr. et Sart., Quer-cus ithaburensis Decaisne ssp. macrolepis (Kot-schy) Hedge). In these cases the vegetative propa-gation was not necessary.

For having a general picture of multiplicationactivity course regarding under-risk species, weeffected quantitative survey of obtained successesboth for vegetative and generative ways, dividingthem in classes, according to recorded percentage(Fig. 3). We did not considered cases when spe-cies did not survived to transplantation.

In the greater part of the cases, both vegetativeand generative propagation shown a success supe-rior to 50%, that could decidedly be improved byeffecting the propagation under checked condi-tions (of temperature, light and damp).

The scarce success cases individualization,above all for generative propagation (for instance:Limoniastrum monopetalum (L.) Boiss, Iris revo-luta Colas., Linum tommasinii Rchb. and others),underlines necessity for further investigations onwhy of the reproductive potential reduction, thatin these cases is transferred in ovulis missed ferti-lization because of incomplete development of theembryonic sack or for non-arrival of pollinic tube.It is known Ca2+ role during germination and ex-tension of pollinic tube and on the stigm, onovary, in vital seeds formation: the correct exog-enous and endogenous concentration is funda-mental for a correct reproductive cycle (Grilli

Caiola 1995). The safeguard necessity of so rare

and spotted distribution species, makes necessaryfurther investigations about reproductive proc-esses which are dependent on exogenous factorsas temperature, photoperiod, damp, nourishingand substratum oligo-elements, but also on en-dogenous factors as chromosomal order, that de-termines the gametofitic compatibility (Accogli

et al. 2006)

CONCLUSIONS

Territory species and habitats recovery passesthrough the study of the reproductive cycles inanimals and vegetables organisms, but, above all,through the study of genetic and epigenetic fac-tors which regulate their themselves cycles,aswell also through the study of microclimatic fac-tors and anthropic action. These factors deter-mine not only the number of individuals in thepopulations, but also their ability to sustainthemselves in course time with production of fer-tile seeds.

The success levels recorded during effectedpropagation tests, can help deciding to use moregenerative rather than vegetative propagation, ac-cording to necessity to have fertile and well de-veloped individuals to re-introduce in originsites; we must however consider that vegetativemultiplication in brief time well developed indi-viduals determines even if it already give anomozygotic.

Fig. 3 — Number of success cases by classes.

348 accogli and marchiori

REFERENCES

Accogli R., Scandura S., Marchiori S., 1999 — Mol-tiplicazione di specie di interesse fitogeograficonell’Orto Botanico di Lecce. Atti 94° Congresso So-cieta Botanica Italiana, 22-25 settembre 1999, Fer-rara.

Accogli R., Marchiori S., Medagli P., Ippolito F.,2000 — Conservazione ex situ di piante delle ListeRosse della Puglia. Primi risultati. In L. Ricciardi,Myrta A., and F. De Castro (Eds), Cahier OptionsMediterraneennes ser.A: Mediterranean SeminarsN. 47 “La Cooperazione Italo-Albanese per la val-orizzazione della biodiversita” CIHEAM, Bari.

Accogli R., Beccarisi L., Medagli P., Zuccarello

V., Marchiori S., 2004 — Conservazione ex situ dispecie vegetali rare e minacciate sul territoriopugliese. Inf. Bot. It., 36(2): 567-568.

Accogli R., Medagli P., Marchiori S., 2006 —Riproduzione ex situ e reintroduzione in situ di Peri-ploca greca L. nella riserva naturale delle Cesine(Lecce). Inf. Bot. (in press).

Accogli R., Nutricati E., Fama L., Medagli P.,

Manno D., De Bellis L., Marchiori S., Colas-

ante M., 2006 — Iris revoluta Colas.: characteriza-

tion and ex situ conservation problems. InternationalSymposium ‘Hybrids & Iris’. Florence, Italy May5TH-6TH-7TH 2006.

Conti F., Manzi A., Pedrotti F., 1992 — Lista RossaNazionale delle piante d’Italia. WWF Italia, SocietaBotanica Italiana, Roma.

Conti F., Manzi A., Pedrotti F., 1997 — Liste RosseRegionali delle piante d’Italia. WWF Italia. SocietaBotanica Italiana, Universita di Camerino, Cam-erino.

Grilli Caiola M., 1995 — Il calcio nei processiriproduttivi delle piante. In: “La riproduzione neivegetali”, Progetto Nazionale fondi 40%. Ministerodell’Universita e Ricerca Scientifica e Tecnologica.Dip. Biol. Univ. Roma “Tor Vergata”.

Marchiori S., Dedej Z., 2000 — Centro studi per laprotezione e la conservazione delle specie botanichedel Mediterraneo con annesso giardino botanico. Lacooperazione italo-albanese per la valorizzazionedella biodiversita, 1° Seminario, Lecce, 2000.

IUCN-BGCS & WWF (1989) — Orti Botanici e strat-egie della Conservazione. Societa Botanica Italiana,Gruppo di lavoro per gli Orti Botanici e i GiardiniStorici, Edizione Italiana 1995.

ex situ conservation and rare plants propagation in the lecce botanical garden etc. 349