COLLECTION OF HEVEA MATERIALS FROM RONDONIA TERRITORY...• •. 1IN BRAZIL: A PRELIMINARY STUDY

2PAULO DE SOUZA GONÇALVES

Seven characteristics were studies in 27 selected wild mother trees at Ouro

Preto, Rondônia Territory namely, yield, circumference, bark tickness, total

number of latex vessel, density of latex vessels per 5 mi 1imeter per ring, and

average distance between consecutive latex vessel rings. AlI the trees were

also evaluated for the degree of incidence of South American Leaf Bl ight

(SALB). Great variability was observed among the individual selected rubber

trees growing under similar envirommental conditions. Linear correlations

among the quantitative characteristics were estimated. Positive co rre 1a tion s

were found between yield and circumfer~nce, bar~ thickness, total number of

latex vessel rings and density of latex vessels per 5mm per ring. No

relationship was found between yield and diameter of the latex vessels and

between yield and average distance between consecutive latex vessel rings.

Regression analysis of yield on other characteristics showed the regression

coefficient to be highly significant to circumference, bark thickness, total

number of latex vessel rings and density of latex vessel per 5mm per ring.

coefficient, genetic variation, selecti,

Index terms - Hevea spp., rubber tree, linear correlation, regressionCollection of Heveao FL-FOL10~11111111111111111111111 11111 111111111111111 1111111111111111111111111 11111111CPAA-11074-1

lThis research has been supported by SUDHEVEA/EMBRAPA agreement. .~ ••••••••••2A .gronomlst M.Sc., in Tree Improvement, Centro Nacional de Pesquisa da

FOL1051

Se r i n que i

ra (CNPSe) - EMBRAPA, P.O.Box 319, CEP 69.000 - Manaus - Amazonas - Brazil.

RESUMO - COLEÇÃO DE MATERIAL DE SERINGUEIRA SELECIONADO NO TERRIT6RIO DE..'-'RONDÔNIA - ESTUDO PRELIMINAR.

RESUMO - Foram estudadas sete características de 27 matrizes selecionadas em Ouro

Preto, no Território Federal de Rondônia. Produção, circunferência, espessura de

casca, nGmero total de an~is de vasos laticíferos em Smm do anel, e distância

média entre os an~is consecutivos de vasos laticíferos foram determinados nas se

leções. Todas as árvores foram aval iadas para o grau de incidência do mal sul-ame

ricano das folhas. Grande variabil idade foi observada entre os indivíduos selecio

nados, vegetando sob as mesmas condições ambientais. Correlações lineares ent re

as características quantitativas foram estimadas. Correlações positivas foram en- - ";,..- ..c. -- .. ,:- -•.'

contradas entre produçao e circunferencia do tronco, espessura de casca, -"umero

total de anéis de vasos laticíferos e densidade dos vasos laticíferos em Smm do

anel. Baixa correlação foi encontrada entre a produção com diâmetro dos vasos la

ticíferos e produção com distância m~dia entre os anéis consecutivos de vasos la

ticíferos. A anál ise de regressão de produção e os valores dos cara~teres quantl

tativos estudados mostram coeficientes de regressao altamente sig~ificativos p~

ra circunferência, numero total de an~is de vasos laticíferos e densidade de va

50S laticíferos em Smm do anel.

Tenmos para indexação - Seringueira,Hevea sp, correlação 1 inear, coeficiente de

regressão, variação genética, seleção.

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INTRODUCTION".J

Conventional breeding takes a long time to provide a few clones with acceptableall-round characteristics for large scale commercial planting. This is because theperennial nature of the erop impose long testing eyeles. In addition, multipleselection for yield and seeondary eharacters whieh are often unfavourably assoeiated wi t h yield, reduces eonsiderably the chances of producing good all-round elones (Ho 1972).

The first botanical expedition with the purpose of collecting botanical materialof native rubber trees (Hev~ spp) was held in 1945 in the Rondônia Territory. Thecollected seeds were planted in 84 hectares but these were destroyed by fire in1950. Later in 1962, a new expedition was designated to recol1ect materiaIs fromthe same treesin the same area (Moraes 1963). Ten years later in 1972, a furtherexpedition was carried out and a Hev~ breeding programme based on the wild mothertrees in jungle was initiated. From the results of previous expeditions, the Acreand Rondônia areas have shown the presence of high yielding vigorous germplasm (Pereira 1972, Gonçalves et alo 1973, Viegas & Gonçalves 1974, Gonçalves 1978, Gonça~ves 1979).

The main objective of wild mother tree selection is to supplement the breedingprogramme by provinding a wider range of good all-round clones in a short time.Data from the most recent eolleetion have been subjected to analysis (mainly thevarious parameters eonnected with yield and vig~r) and the preliminary findings arereported in this paper.

MATERIALS ANO METHODS

Selection of high yielding wild mother trees

Simmonds 1969 emphasised that multiplicity of characters selected always eitherdemanded large populations or caused a weakened selection for individual characters. The leveI of operation to cope with the former alternative is not praticalin a conventional breeding programme. However, by resorting to commercial and otheradvanced generation seedl ings, it is feasible to screen large populations by massselection.

. .....•.

A particularly conducive situation favouring such an approach in Brazi1 is theready availabi1 ity of large areas of hi~h yielding wiíd trees.

In the pre-selection of mother-trees in the fie1d, the basic objective was toidentify the best yie1ding phenotypes for further yield recording and observation .The fLndings from the pre1iminary investigations by Gonçalves 1978, have been usedin the processo For the pre-selection of the wi1d mother-trees, the tappers (Figure1) were contacted for location of the high yie1ding trees giving more than 1000 ccof 1atex per tapping. This information was verified and confirmed. Freedom frorn!vU..CJtoc.tjc.1.w., u.i.e.i and Phtj;toph:thoJta sp. 1eaf fa11 was cheked vi sua11y (Figure 2). Budwoods from orthotropic branches were then co11ected, the cut ends waxed and stored

moist saw-dust and sent to National Rubber Research Centre at Manaus andgrafting.

Yie1d, number and heigh of panel, circumference at 1.5m height and degree ofdisease incidence were recorded for each se1ected tree. Bark samples were taken forrecording the tickness, total number of 1atex vesse1 rings, diameter of 1atex vesse1s, density of 1atex vessels per 5 mil imeter per ring and average distance between consecutive 1atex vesse1 rings based on a11 rings. The sample were taken atprecise1y 1.5m above the soi 1 surf~ce (Tab1e 3). B~dwood from 27 trees was then co11ected.

Bark Characteristics Measurements

The fo11owing bark characteristics were measured in the bark sample:

Bark tlíickness;

Total number of latex vesse1 rings was determined by examining thelongitudinal sections of the bark;

radial

Diameter of 1atex vesse1s was observed in the tranverse section of thebark;

Density of latex vesse1s per 5mm per ring determined by the average densitybased on a11 rings;

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Average distance between consecutive latex ves?el rings was determined basedon a ll rings. 'J •

Estimates of correlation between the seven characters were computed from data ofselected individuaIs.

RESULTS AND DISCUSSION

Variation of the Sampled Trees••

Great variability was observed a rn o n q the individual selected rubber trees ofdifferentf ages growing under the same environmental conditions. (Table 3).

Ule (1905) and Baldwin (1974) have mentioned that very high yielding trees arefound in the Ouro Preto area of Rondonia Territory of Brazi 1 (Figure 3).

The morphological characters of the trees studied followed the description of~ ~ • J • • • •••.••• O"

Heve.a. bJtaf.,,éLéelU,u,as given by Seibert (1974). It was noted that the majority oftrees in this area, including those collected, had purple cortical tissue (Figure 4),but the latex of alI trees was white. A rough estimate of the age of the trees basedon the girth showed a variation from 20 to 300 years. Total number of latex vesselrings per tree ranged from 19 to 7l. Bark thickness ranged from 0.61 to 2.42cm inthe trees (Table 1). Part of the observed differences in the latter characteristicswas associated with the difference in tree circumference. Number of panels was alsoassociated with the magnitude of circunference (Table 2).

Disease Incidence

The Hevea tree defol iates and renews its foI iage annually and this phenomenon iscommonly known as wintering. UnI ike the trees in temperate countries wheredefoliation occurs during the winter period of the year, in Hevea b4aD~elU,u, whichgrows in the tropics this takes place during the drier months of the year .

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In addition, the incidence and severity of infection of the disease is stronglyinfluenced by the prevail ing cl irna t ic c.,pnditions dur iaq the wintering time.Regions having a high and well distributed rain falI with no pronounced dry seasonare observed to have severe disease incidence while areas receiving moderaterainfall but without a long dry season may have disease incidence intermediatein severity. Therefore, the prospected area which showed a extended drought· forabout months, receiving ponderate intensities of rainfall, experienced only lowincidence of MiCJ1.oc.yc1.u...6 u1.eJ.. and Phy:toph-t.hoJUl. sp. in the f o l iage.

~EMBRAPACG) C N P 5 o~ BIBLIOTECAYield-Bark Characteristics Relationship

Correlation studies for circumference, bark thickness, total number of latexve~sel rings and diameter of the latex vessels in the collected material were ingood agreement with the findings of various workers (Wycherley 1969, Narayanan etalo 1973; Ashp1ant 1928) with clonal rubber tree selections. Linear corre1ationsbetween yield and bark characteristics such as thickness (r=0.7290**) , total number of latex vessel rings (r=0.5l39**) and density of latex vessels per 5 mil limeters(r=0.5397**) , were significant at the 0.01 leveI (Table 4). Thus 53 percentof the total variation was associated with bark thickness. The magnitude of thecorre1ation (r=0.7290) for bark thickness is in close agreement with the r=0.8089reported by Gonçailves et al. (1980), who used one year old clone.. A1thoughBrookson (1959) showed that was positive correlation between the yields ofindividual mature seedl ings and c10nes derived frQm them, Wycher1ey (1969) ,pointedout that this evidence was inadequate.A similar situation may also exist for thecollected material in this study. In view of the above, it is still necessary torepeat the test of the budgrafts made from these collections for further selection. It would be interesting to see whether col1ections from different geographicareas of Brazil show different behaviour.

Yie1ds of alI selected rubber trees were regressed on their bark characteristi~.Table 5 shows the simp1e 1inear regression equations of yie1d (y) on the sixvariables. The analysis indicated that the slope of the regression Iine wassignificant at the 0.01 leve l (F=28.36**) for bark thickness, indicating thatbark thickness is closely related to yie1d, independent of the age of the tree.

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A similar situation possibly existed for total number of latex vessel rings anddensity of latex vessels per 5mm p~r r-jng. For both cnaracteristics the slope ofregression lines (F=8.97**) and (F=IO.27**) respectively (Figure 5) indicated thatwere closely related to yield of the trees.

CONCLUSIONS

Hevea breeders recognise the difficulty of producing good all-round clonesquickly. Fresh approaches have therefore been sought. One of these is by mother-tree selection from populations of wild rubber trees. The main altractions ofsuch an approach are as follows:

No contraI led crossing is necessary;

No capital outlay for land is required as these populations are in thenative environment.

The early results from the wild--mother-tree selection are promising.

Positive and significative correlations were foundbetween yield andcircumference, yield and bark thickness, yield and total number of latexvessel rings, and yield and density of latex vessels per 5mm per ring.

No relationship was found between yield and diameter of-the latex vesselsand between yield and average distance between consecutive latex vesselrings.

_ Regression analysis of yield on other characters showed the regressioncoefficient to be highly significant for circumference, bark ticknesstotal number of latex vessel rings and the density of latex vessel per 5mmper ring. The regression coefficient of diameter of the latex vessels andaverage distance between consecutive latex vessels rings was nor signiiicanto

There is need to repeat the tests of budgrafts made from this collection andit would be of interest to see whether latex collections in different geographicareas of Brazil differ in behavior.

• .ao '-

ACKNOWLWDGEMENTS

The autor is grateful to Mr. Afonso C.C. Valois, the Head of the Scientific

Staff of CNPSe for his valuable suggestions. The assistence of Mr. Antonio Pe~

soa Rebell0 in the determination of bark characters is grateful ly acknowledged.

Acknowledgements are also due to Misses Maria E.C. Vasconcellos and Maria A.C.

Neves for statistics work and designs.

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REFERENCES

ASHPLANT, H. Investigations into He.ve.a anatomy. Bu11 Rubb.Grow., 10(7): 484. 1928.

BALDWIN, Jr. J.I. He.ve.a: A fi rst interpretation. J.Heredit., lQ(2): 54-64. 1947..BROOKSON, C.W. Seed1ings and c lone s of Heve.a bJta6..ilienó.i6. In: WORLD CONGRESS OF

AGRICULTURAL RESEARCH, 1., Rome, 1959. Proceedings. Rome, s.ed., 1959. p.699.1959.

GONÇALVES, P.de S. Seleção e coleta de seringueiras nativas à margem dos rios Mamo• ré, Guaporé e são Migue1 - Território Federal de Rondônia (Report). Manaus

EMBRAPA-CNPSe, 1978. 43p.

GONÇALVES, P. de S. Seleção e coleta de seringueiras nativas da região de Ouro Prero - Território Federal de Rondônia (Report), Manaus, EMBRAPA-CNPSe, 1979. 44p.

GONÇALVES, P. de S.; MATOS, A.P.; MULLER, M.W. & VI EGAS, I.J.M. II coleta de materia1 nativo de alta produção em seringais do Estado do Acre e Território Federalde Rondônia (Report). Be1ém, IPEAN, 1973. 24p .

••• • J •

GONÇALVES, P. de S.; VASCONCELLOS, M.E.C.; VALOIS, A.C.C. & BARCELOS, E.S. Herdabi-1idade, correlações genéticas e fenotípicas de algumas características de c10nesde seringueira (He.ve.a spp). Pesq.Agropec.Bras., Brasí1ia, 15(2): 129-36, abro1980.

HO, C.Y. Investigation on shortening the geverative cyc1e for yie1d improvement inHe.ve.a bJta6~e.nó~. New York, Corne11 University, 1972. Tese Mestrado.

MORAES, V.H.F. Seleção em seringais nativos Circ.IPEAN, Be lern (])~ 1-32, 1963.

NARAYANAN,-R=;_~OMEZ, J.B. & CHEN, L.T. Some structura1 factors affecting the pr~ductivity of He.ve.a bJta6~e.nó.i6. II Corre1ation studies between structura1 factors and yie1d. J.Rubb.Res.lnst.Ma1aya, Q(4): 285, 1973.

PEREIRA,_J. da P. Coleta de material silvestre de alta produção em seringais nativos do Acre e Estação de Porto Velho (Repo rt }. Belém, IPEAN, 1972. 9p.

SEIBERT, R.J. A study of He.ve.a (with it's economic as pe c t s) in the Repub1ic ofPeru. Ann.Mo.Bo1.Gdn., 34(12): 261-350, 1974.

SI MMONDS, N. VI.

1, 1969.

Genetica1 bases of p1ant breeding. J.Rubb.Res.lnst.Ma1aya, 21(1):

•

IIULE, E. Die Kautschukpf1anzen der Amazonas Expedition und ihre Bedeutung fur die

Pflanzengeogr phie. l n : Eng1er's Botan. Jahr bliche r , 1905.

VIEGAS, I. de J.M. & GONÇALVES, P. de S. 111 coleta de material nativo de alta

produção em seringais do Estado do Acre e Território Federal de Rondônia (R~

po r t }. Be1ém, IPEAN, 1974. 46p.

WYCHERLEY, P.R. Breeding in He.vea... J.Rubb.Res.lnst.Ma1aya, 21(1): 38-55,1969.

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•TABLE 1 - Overal 1 means, standard deviation and coefficients of variation of 27 mother trees colected fromPreto, Federal Territory of Rondônia. (Brazi 1). Manaus, 1980.

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Characteri st ic RangeMean Units Standarddeviation

Coefficient ofvariation (%)

Yield/tapping/tree

C ircu mfe ren ce

Bark thickness

Total number of latex vessel rings

Diameter of latex vessel

Density of latex vessels per 5mmper ring

Average distance between consecutivelatex vessel rings

2.85 0.50 - 6.00

4.74 0.61 - 4.13

1. 49 : 0.61 - 2.42

36.40 19.00 -71.00

44.18 18.30 -24.40

375.38 208.84-521 .32

1i t re 1.33 46.7

2.55 53.8

0.38 25.5

10.34 28. Lf

23.40 52.9

98.20 26.2

m

mn

mm

289.38 i06. 10-482. 80 mm 68.71 23.7·

TABLE 2 - Number of trees and their yield, circumfe,rence range and number of panels intherrother

tr~ék collected in Ouro Preto, Federal Territory of Rondônia. (Br az i l ) Manaus 1980.I i

lIII

N~ of trees Y ie 1d (1 i t re) Ci rcumference Range '(rre t r es) N~ of panels in exploration

0.5 0,61

2 1.0 0.85-1.71 1, 3

3 1.5 1.50-2. 16 1, 4 e 6(

3 2.0 1.88-2. 18 3, 3 e 3

3 2.5 1.46-2.85 2, 3 e 5

8 3.0 I 1.78-3·70 3, 3, 3, 4, 4, 5, 5 e 6

3·5 3.80 7 •2 4.0 2.29-2.60 5 e 5

3 5.0 2.65-4. 13 4, 6 e 7

6.0 3.47 8

.'

llhe col'ected rrothertrees were cloned at National Rubber Research Centre as CNS-RO 7901 to CNS-RO 7927

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TABLE 4 - Linear corr1e1ation coefficients between yie1d and the va r lous structural parameters of the27 mother trees co11ected in Ouro Preto, Territory of Rondônia. (Brazi 1) Manaus 1980.

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I'• IParameteres 51mb,q1 Y C B T.V.R. D.L.V.

_ I.D.V.R. A.D.e.V.

IYie1d/t/t Y i 1 0.7304** 0.7290** 0.5139** 0.3464 n.s.

Bark thickness B 0.6765** 0.4302**

0.5397**

0.4536**

0.6585**

0.3355 n.s.C! rcumference C 0.7894** 0.4380* 0.4274** 0.4508**

0.5002**Total number of 1atex

ves se l rings T. V. R. 0.2721 n.s. 0.9623** O • 1155 n. s .

Diameter of 1atex vessels D. L. V. o . 36 91 n. s . ",O. 1 155 n. s .

Density of latex vesselsper 5 (mm) per ring O.V. R. 0.0534 n.s.

Average distance betweenconsecutive 1atexvessels per ring

I,

A. D.e. V.'.

(* ) Diference significant at 5% leve1 of probabi1ityli.

(**) Diference significant at 1% 1evel of probabi 1ity

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1

111

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TABLE 5 - Linear regression equations between yield and various structura1!IFharacters of the 27 mother trees col1ected from Ouro Preto, Federali0erritory of Rondônia (Brazi 1) - Manaus, AM. 1980

Regression of yield (y) on y Regression Coefficient

I"

(e)

(B)

(T.V.R.)(O.V.L.)

1.059 + o. 46 1 (e) 0.461**

-0.940 + 2.540 (B) 2.540**o . 576 +0. 063 (T.V .R.) 0:063** (

3.724 + 0.297 (O.L.V.) 0.297 n.s.-0.040 + 0.007 (O.V.R.) 0.007**

;.

0.081 + 0.006 (A.o.e.v.) 0.006 n.s.•

,(c.v. R.)

(A.o.e.v.)

',I(**) Difference significant at 1% .leve1,of probabi lity

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Figure 1. Natíve tapper carrying out' tappingamecí wi1th a rifle anda kerosenehead 1ight.

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Figure 2. Víew of" the tree Leaves wiít.fuJlight incídenc~ aí M. ulei.

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GROSSO

STATE

plrnRE 3 -Localizat:ÍlolilJ of OUro Prêt0\ where the tTees- were

col.Iec ted :iilJll the Territary of Rondôni.a .'

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Fig:w:re 4 - Hev<}-a. b.1/:J::U·ilie}'f;~-.iA· wi th purp] e

ba rk est.irnated to be 60 yearsold frorn Ouro Preto.

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-0040+ 0.007x- 3.724 +0.297xy y

6 r 0.5163 6 0.3457

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, I I'200 300 400 500 600 700· O 18 20 ?2 ?4 26 28

Densrt y of lote). ve s s e ls per 5 rrrn ú,oMeler of ve s set r Ings (~m)

- 0.0808 + O0:16x- O 576 - 0063)(y y

60.3355 6 04945

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ti , , ,O I ZOO 250 3=>8 35J 400 450 500 O 10 20 30 4C 50 60 70

ú,51onct lJel we er. cO':s t-:ú. I li e 101 e x v e s s e! r"Jôl/Le: o~ 1(, ; ( , "t"d ',é: r HI;;~r mg5 (tJm)

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Figure 5- Relatianship of yi eId with ci rcumference , bark t.hirckness dcnsuty of latexvessels per Srrnn)cliameteTaf ves se-ü r ings , dist.ance between consecut iveIatex ves se'I rings and number of vesse l r íngs of the trees collected ofOuro Preto. Territory of Rondônia.

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