One hundred and eighteen accessions of the Leucaena genus were assayed for extractable and bound condensed tannins (CT). Leucaena taxa varied from low or no CT (0-1%) to extremely high levels (\u3e15%). There was considerable intraspecific variation in CT within key taxa. The proportion of bound tannin decreased with increasing total CT content

Dalzell, S A

Shelton, H M

English

University of Kentucky

Session 1 - Conservation, Evaluation and Utilization of Plant Resources 1-105ABSTRACTOne hundred and eighteen accessions of the Leucaena genus wereassayed for extractable and bound condensed tannins (CT). Leucaenataxa varied from low or no CT (0-1%) to extremely high levels(>15%). There was considerable intraspecific variation in CT withinkey taxa. The proportion of bound tannin decreased with increasingtotal CT content.KEYWORDScondensed tannins, leucaena, genotypic variationINTRODUCTIONA comprehensive collection of accessions from the Leucaena genus,compiled from international germplasm collections, was evaluatedfor condensed tannins. The study formed part of a larger andcomprehensive program of evaluation of the agronomic and foragequality characteristics of the Leucaena genus being conducted byThe University of Queensland with support from the AustralianCentre for International Agricultural Research (ACIAR). Condensedtannins (CT) have been implicated in both adverse and beneficialeffects on animal nutrition and have been found to occur in significantconcentrations in a number of tropical forage tree species eg.Calliandra (Shelton et al. 1996). Selection of agronomically desirableaccessions must be coupled with knowledge of their CT status. Highconcentrations of CT in plant tissues will adversely affect foragequality. Consequently, the objectives of the experiment were toidentify and quantify genotypic variation in CT concentration inLeucaena spp.MATERIALS AND METHODSA Leucaena germplasm collection of 118 accessions under evaluationby the ACIAR Project was established at The University ofQueensland research farm at Redland Bay (27o37’S:153o19’E) in1995. The youngest fully expanded leaves of each species (YFEL)were sampled, field frozen, and lyophilized on the 8/4/96 (Dalzelland Shelton, 1997). The extractable CT (ECT) concentration wasmeasured using the technique developed at The University ofQueensland by Dalzell and Kerven (1997) and total-bound CT(TBCT) content was estimated using the method of Perez-Maldonadoand Norton (1996). TBCT measurements estimate the combinedprotein-bound and fibre-bound CT present in sample residues afterthe removal of ECT. All CT concentrations were expressed asLeucaena pallida CT equivalents based on the use of a L. pallidastandard CT in the proanthocyanidin assay.RESULTS AND DISCUSSIONTotal condensed tannin (TCT) concentrations in 118 accessions ofthe Leucaena genus varied widely from 0 – 30.6 % DM TCT in theyoungest fully expanded leaves (YFEL) sampled (Table 1). Ingeneral, the genus could be divided into four categories on the basisof TCT concentrations. These were:(a) Species/subspecies with low or no TCT (0-1%) including L.collinsii collinsii, L. collinsii zacapana, L. shannonii magnifica,L. lempirana, L. lanceolata sousae, L. salvadorensis, L.trichodes.(b) Species/subspecies with medium TCT (1-7%) including L.lanceolata lanceolata, L. leucocephala glabrata, L.leucocephala ixtahuacana, L. leucocephala leucocephala, L.ID NO. 1998GENOTYPIC EFFECTS ON CONDENSED TANNINS IN THE LEUCAENA GENUSS.A. Dalzell and H.M. SheltonDepartment of Agriculture, The University of Queensland, Australiamacrophylla, L. macrophylla nelsonii, L. multicapitulata, L.retusa, L. shannonii shannonii, KX2 hybrids L. pallida x L.leucocephala glabrata, KX3 hybrids L. diversifolia diversifoliax L. leucocephala glabrata.(c) Species/subspecies with high TCT (7-15%) including L.diversifolia diversifolia, L. diversifolia stenocarpa, L. esculentaesculenta, L. esculenta matudae, L. involucrata, L. pallida, L.pueblana, and(d) Species/subspecies with extremely high TCT (>15%) includingL. confertiflora, L. cuspidata, L. greggii, L. pulverulenta.There was also considerable intraspecific variation in TCT withinkey taxa including:L. leucocephala glabrata 0.5 – 4.0%L. diversifolia diversifolia 5.7 – 18.5%L. diversifolia stenocarpa 0.4 – 22.6%L. pallida 4.9 – 11.6%Generally, the proportion of total bound CT, increased with increasingTCT concentration. At very low TCT (<1%), the majority was inbound form, between 5-15% TCT approximately 10-30% was inbound form, whilst above 15% TCT approximately 10% was in boundform (Table 1).In conclusion, there was considerable genotypic variation in CTconcentrations detected in the YFEL of Leucaena spp., with thepotential to select lines that have low levels of CT, both between andwithin taxa. It is also possible to select psyllid resistant Leucaenaaccessions that are low in CT (e.g. L. collinsii collinsii).ACKNOWLEDGEMENTSWe acknowledge the assistance of R.C. Gutteridge, B.F. Mullen, M.Faint and A.K.M. Shamsul Islam in the collection of data. We alsoacknowledge the funding assistance of the Australian Centre forInternational Agricultural Research (ACIAR).REFERENCESDalzell, S.A. and G. Kerven. 1997. A Revised Method forCondensed Tannin Analysis of Leaf Tissues in Leucaena spp.Proceedings XVIII International Grassland Congress, 8-17 June,Manitoba and Saskatchewan, Canada. in press.Dalzell, S.A. and H.M. Shelton. 1997. Methods of field preservationand selection of sample tissue for condensed tannin analysis inLeucaena species. Animal Feed Science Technology. in press.Perez-Maldonado, R.A. and B.W. Norton. 1996. The effects ofcondensed tannin from Desmodium intortum and Calliandracalothyrsus on protein and carbohydrate digestion in sheep and goats.British Journal of Nutrition 76:515-533.Shelton, H.M., B.W. Norton, B.F. Mullen, R.C. Gutteridge andP.J. Dart. 1996. Utilisation and nutritive value of Calliandracalothrysus for forage: A review of research at The University ofQueensland. Pages 210-221, in D.O. Evans, ed. InternationalWorkshop on the genus Calliandra, Bogor, Indonesia, January 23-27, 1996. Winrock International. pp. 210-221.Session 1 - Conservation, Evaluation and Utilization of Plant Resources 1-106Table 1Condensed tannin (CT) concentrations in species and subspecies of the Leucaena genus.Species Subspecies No.                 Extractable                 Total Bound                     TotalAccessions CT % FDWt  CT % FDWt CT% FDWtMean Range Mean Range Mean RangeL. collinsii collinsii 2 0.0 0.0-0.0 0.1 0.1-0.1 0.1 0.1-0.1L. collinsii zacapana 3 0.0 0.0-0.0 0.2 0.1-0.2 0.2 0.1-0.2L. confertiflora 2 19.4 15.2-23.5 2.1 1.6-2.7 21.5 16.8-26.2L. cuspidata 1 29.1 - 1.5 - 30.6 -L. diversifolia diversifolia 12 10.8 4.0-16.6 2.1 1.1-3.8 12.9 5.7-18.5L. diversifolia stenocarpa 12 8.5 0.2-20.5 2.0 0.2-3.1 10.4 0.4-22.6L. diversifolia x L. leucocephala 10 4.1 1.7-7.3 1.2 0.4-1.8 5.2 2.1-9.1L. esculenta esculenta 2 11.2 10.0-12.3 1.3 1.2-1.4 12.5 11.2-13.7L. esculenta matudae 1 12.3 - 0.9 - 13.2 -L. greggii 1 18.4 - 1.3 - 19.7 -L. involucrata 1 13.5 - 1.3 - 14.8 -L. lanceolata lanceolata 4 0.7 0.3-1.2 0.4 0.2-0.5 1.0 0.6-1.6L. lanceolata sousae 2 0.2 0.2-0.2 0.1 0.1-0.1 0.3 0.3-0.3L. lempirana 2 0.2 0.2-0.2 0.1 0.1-0.1 0.3 0.3-0.4L. leucocephala glabrata 22 1.8 0.5-4.0 0.8 0.4-1.3 2.6 0.9-4.8L. leucocephala ixtahaucana 1 4.2 - 0.9 - 5.1 -L. leucocephala leucocephala 3 1.6 1.2-2.2 0.8 0.5-1.2 2.4 1.7-3.5L. macrophylla macrophylla 2 1.3 0.9-1.7 0.3 0.3-0.4 1.6 1.3-2.0L. macrophylla nelsonii 2 0.8 0.6-1.0 0.4 0.2-0.6 1.2 1.2-1.2L. multicapitula 2 0.5 0.0-1.1 0.6 0.2-0.9 1.1 0.2-2.0L. pallida 9 6.9 1.8-15.9 1.0 0.6-1.6 7.8 2.4-17.1L. pallida x L. leucocephala 5 4.4 3.0-6.1 1.2 1.2-1.2 5.6 4.2-7.3L. pueblana 2 10.0 9.3-10.6 0.5 0.5-0.6 10.5 9.9-11.1L. pulverulenta 3 14.6 11.8-18.3 1.3 1.0-1.8 15.9 13.0-19.4L. retusa 1 2.3 - 1.2 - 3.5 -L. salvadorensis 3 0.0 0.0-0.1 0.2 0.1-0.2 0.2 0.2-0.2L. shannonii magnifica 2 0.0 0.0-0.0 0.1 0.1-0.1 0.1 0.1-0.2L. shannonii shannonii 4 0.7 0.0-1.7 0.5 0.4-0.7 1.3 0.5-2.3L. trichodes 2 0.1 0.1-0.1 0.2 0.1-0.2 0.2 0.2-0.3Notes:* CT measured in L. pallida condensed tannin equivalents* FDWt=Freeze-dried weight

Genotypic Effects on Condensed Tannins in the Leucaena Genus

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Genotypic Effects on Condensed Tannins in the Leucaena Genus

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