Pigeon pea for fallow improvement in slash-and-burn systems in the hills of Laos?

Calliandra calothyrsus has been reported to have potential for agroforestry in the humid lowlands of West and Central Africa. Provenance evaluation of the species was initiated in Yaounde, Cameroon with the objective of identifying adapted provenances with desirable traits for inclusion in evaluation of the management of various agroforestry technologies being developed for the humid lowlands of the region. Fifteen provenance seed collections from Central America and southeast Asian sources were included in the trial. Results indicate that enormous genetic variation exists between these provenances. The highest yielding provenance produced 1.8 and 2.5 times, respectively, wood and leaf biomass compared to the lowest yielding provenance. Most of the provenances evaluated flowered during the first six months after establishment while all the provenances (15) flowered by the end of the first year. However, this initial flowering did not result in productive pod development and seed setting. Two years after planting, the trees were cut at a height of 0.05 m above ground level, and more than 80% of the stumps of all the provenances re-sprouted. Leaf nitrogen content ranged between 2.25% and 2.78% of dry weight. Six provenances had above average values in at least five of the six desirable traits considered i.e.: height, growth, stem development, leaf biomass, wood biomass, leaf litter productivity and total nitrogen content of leaves; these are recommended for further testing for inclusion in appropriate technologies for soil fertility improvement. This revised version was published online in June 2006 with corrections to the Cover Date.     

Rooting ability of Calliandra calothyrsus leafy stem cuttings in a non-mist propagator

It was the aim of this study to determine if Calliandra calothyrsus could be vegetatively propagated in a low-tech non-mist propagation environment suitable for the rural tropics. In addition, within and between provenance variation in the rooting ability of C. calothyrsus was determined. Leafy stem cuttings were propagated successfully in non-mist propagators, with 100% rooting success recorded for some genotypes. The average rooting potential of the best rooting provenance was 76% for San Ramon provenance from Nicaragua. Cuttings harvested from stockplants grown from seed collected at La Ceiba, Honduras, were also successful with 65% rooting; while the least successful provenance was Suchitepeques, Guatemala, which did not form adventitious roots. It is concluded that low-tech vegetative propagation is a viable means of providing planting stock of C. calothyrsus, and that the development of operational scale propagation procedures would be worthwhile.     

Effect of rhizobial inoculation on growth of <Emphasis Type="Italic">Calliandra</Emphasis> tree species under nursery conditions

A nursery experiment was conducted in un-sterilized soil in Senegal using six Calliandra species or provenances inoculated with a mixture of seven rhizobial strains. Plant growth was assessed periodically at 1, 2, 3, 12 and 18 months whereas nodulation, shoot and root dry weights were assessed at 12 and 18 months after planting (MAP). Un-inoculated seedlings of all the six species died at 12 months after planting. Results of growth assessments were variable with significant differences (P < 0.05) between C. calothyrsus Meissn provenances (Flores and San Ramón) and C. juzepczukii Standley in height at 1, 2 and 3 MAP. Shoot dry weights of San Ramón provenance of C. calothyrsus Meissn were also significantly different from those of C. acapulcensis (Britton and Rose) Standley and C. longepedicellata (Mc Vaugh) H. Hern and Macqueen at 18 MAP. In contrast, C. glandiflora (L’Her.) Benth grew poorly and did not nodulate. Although rhizobial inoculation improved shoot and root dry weights some differences were observed among the Calliandra species in response to the inoculation, which suggested the occurrence of interaction between the rhizobial strains and the host plant species tested.     

黄皮树种源苗木性状遗传参数及其相关选择效率研究

对湖南省黄皮树１１个种源１年生苗木４个性状组２０个性状的遗传参数及其相关选择效率作了测定和分析。其结果表明：（１）４个性状组中,１７个性状在种源间存在显著差异,其中,生产力性状组的性状表型及遗传变异系数较大,而幼苗、复叶和地上生长性状组的表型及遗传变异较小;（２）地上生长性状间、生产力性状间及其相互间具有显著的表型相关和遗传相关,这为黄皮树地上与地下、生长与生产力性状间的相关选择提供了理论依据;（     

Autumn frost hardiness in Norway spruce plus tree progeny and trees of the local and transferred provenances in central Sweden

Reforestation with provenances from locations remote from the planting site (transferred provenances) or the progeny of trees of local provenances selected for superior form and vigor (plus trees) offer alternative means to increase yield over that obtained by the use of seed from unselected trees of the local provenance. Under Swedish conditions, Norway spruce (Picea abies (L.) Karst.) of certain transferred provenances generally has an advantage in productivity relative to the local provenance comparable to that of progeny of plus trees. The aim of this study was to explore the extent to which productivity gains achieved by provenance transfer or the use of plus tree progeny are associated with reductions in autumn frost hardiness, relative to that of trees of the local provenance. In a field trial with 19-year-old trees in central Sweden, bud hardiness was tested on four occasions during the autumn of 2002. Trees of the local provenance were compared with trees of a south Swedish provenance originating 3 degrees of latitude to the south, a Belarusian provenance and the progeny of plus trees of local origin. The Belarusian provenance was the least hardy and the local provenance the most hardy, with plus tree progeny and the south Swedish provenance being intermediate in hardiness. Both the Belarusian provenance and the plus tree progeny were significantly taller than trees of the other populations. Within provenances, tree height was negatively correlated with autumn frost hardiness. Among the plus tree progeny, however, no such correlation between tree height and autumn frost hardiness was found. It is concluded that although the gain in productivity achieved by provenance transfer from Belarus was comparable to that achieved by using the progeny of plus trees of the local provenance, the use of trees of the Belarus provenance involved an increased risk of autumn frost damage because of later hardening.     

Variation of heartrot,sapwood infection and polyphenol extractives with provenance of Acacia mangium

Infection of heartwood by decay fungi (heartrot) is a concern for growers of Acacia mangium for solid‐wood products as the incidence can be high in some regions of Indonesia. Variation of heartrot incidence for different provenances of A. mangium was determined using two field trials in Sumatra, Indonesia. In a Riau Province trial of 21 provenances, the effect of provenance was statistically significant for natural heartrot incidence, which ranged from 1.6% to 27.2%. In a smaller trial using artificial inoculation in South Sumatra, heartwood infection incidence ranged from 39.4% to 70.8% across six provenances and both wound type and provenance were statistically significant factors. There was also significant variation in sapwood infection length related to provenance. Wood extractives (yield, total phenols, protein‐precipitable tannin and 2,3‐trans‐3,4′,7,8‐tetrahydroxyflavanone) were quantified from a subsample of trees for each trial. However, no significant differences in extractive concentration were detectable according to provenance and evidence for a relationship between heartwood extractives and heartrot incidence was generally poor. While further studies need to be completed to establish the basis for heartrot incidence, results from these trials allow for recommendations on provenance selection to reduce heartrot incidence and provide information for further genetic selection programmes.     

马尾松种源对磷肥的遗传反应及根际土壤营养差异

利用5a生马尾松种源与磷肥互作试验林，研究不同种源对磷肥的遗传反应式样以及在低(缺)磷环境下的根际营养差异。结果发现，广东高州和广西岑溪两种源对磷肥的反应显著，属于对磷肥敏感型种源。广东信宜和福建武平两种源对磷肥反应不敏感，属于耐低磷型或对磷肥不敏感型种源，而江西崇义种源显著的磷肥效应仅在造林后头2～3年显示。对于根际土的的化学性质，不同种源虽有较大差异，但根际土的有机质、全氮、水解氮和有效磷含量一般显著高于非根际土。不同种源根际对土壤中的磷都具有活化作用和富集作用，尤其是广东信宜和福建武平两种源对土壤磷的活化和富集作用最为强烈，这可初步解释这两个种源对磷肥不敏感、能适应低(缺)磷胁迫的遗传机制。马尾松不同种源根际土壤并未发生明显的酸化。     

木荷种源苗期干物质积累和分配差异

利用28个木荷种源的苗期测定材料,研究了不同种源的干物质积累和分配规律。结果显示:木荷苗期单株及其根、茎、叶各器官的干物质积累量在不同种源区间和种源区内不同种源间存在显著的遗传变异,这种变异主要来源于种源区内种源间,其次是来源于不同种源区间。木荷苗期单株及各器官的干物质积累量呈典型的纬向渐变模式,即南部种源区>中部种源区>北缘种源区,而与经度的相关性较小。研究发现,不同种源区间木荷干物质积累量在地下和地上部分的分配比例(即根冠比)遗传分化较小,变异主要来源于种源区内种源间,木荷种源根冠比表现为随机变异的地理模式,自然分布区内降雨量丰富,较少干旱胁迫可能是其主要的原因之一。     

白榆种源的地理变异和基因型稳定性

本文报道了在14个试验点所作46个种源的地理变异和生态稳定性研究结果。发现我国白榆种源间存在着极大的异质性。生长力随纬度方向呈渐变模式,分布区南部黄淮流域的种源生长快,分布区北部各种源生长慢。试验点生境的优劣,对白榆生长影响很大,并存在有一定的种源×地点的交互作用。因此,根据多点的综合分析,提出了各种源的生产力和生态稳定性参数,为各造林地区选用适宜种源提供了依据。     

Geographic variation in tree growth and wood density of <Emphasis Type="Italic">Guazuma crinita</Emphasis> Mart. in the Peruvian Amazon

Guazuma crinita Mart. is a fast-growing timber tree in the Peruvian Amazon. A trial of 11 Peruvian provenances was established in three planting zones. Tree growth at 6, 12, 18 and 30 months and wood density at 32 months were analyzed across and within zones. Zones accounted for more variation than provenances. Density varied significantly due to provenances in the analysis across zones, whereas growth exhibited strong provenance by zone interactions. The local provenance grew well and produced relatively dense wood in all zones. The relative magnitude of variation due to provenances depended on the planting zone. Density was greater in the lower than in the upper stem. Density increased with longitude from the more humid to the drier part of the sample region. In general, correlations indicated that larger trees had lower density and a larger difference in density between the lower and upper stem, but the strength of these relationships depended on the provenance and zone. Results suggest that fast-growing provenances can be selected at an early age without significantly reducing wood density. The local provenance is recommended for reforestation pending future research demonstrating the superiority of foreign provenances. Some practical implications for tree-improvement programs are discussed.     

STUDY ON THE PROVENANCE TEST OF DAHURIAN LARCH SELECTION OF BEST PROVENANCE

In this paper,it is studied that the growth characters of the progeny of 16provenance of larix gmelinii within the all 13 experimental sites by means of the analysis of va-riance,provenance stability,productivity index,rank correlation,synthetic index selection andPCA.The provenances were divided into three patterns:The first type have low and steady prod-uctivity;The second type have high but unsteady productivity;The third type is between theproductivity of the first and second type.Through the analysis on the feasibility and the reliabili-ty of the provenance early selection,the best provenances which lie in the southeast of theXiaoxingan Mt.are regarded as the best and suitable for a large afforestation areas of Larixgmelinii.Then in the north of Xingan Mt.,the local or the northwest provenances of theXiaoxingan Mt.should be used.The genetic gain was calculated on the basis of the provenanceheritability and the utilization of the best provenance were evaluated in this paper.     

Tephrosia species and provenances for improved fallows in southern Africa

Seeking an alternative to Sesbania spp. tree fallows, a Tephrosia species and provenance trial was conducted at Msekera Research Station, Chipata (Zambia) to evaluate eleven Tephrosia vogelii and three Tephrosia candida provenances. They were tested for biomass production, quality of biomass, resistance to root-knot nematodes, nitrogen release, and for their effects on soil nitrogen dynamics. At the end of 1.5 years, the T. candida provenances 02970, 02971 and 02972 from Madagascar produced two times greater amount of aboveground biomass than the T. vogelii provenances. There was little variability among the T. vogelii provenances in terms of litter and biomass production. Weed growth was significantly greater under T. vogelii than T. candida provenances. While Tephrosia vogelii provenance 98/02 from Zambia and T. candida 02972 were highly tolerant to the Meloidogyne incognita nematodes, T. vogelii provenances 02977, 98/03, 02973 from Kenya, Zambia and Malawi, respectively, were highly susceptible to the nematodes. The Tephrosia species and provenances showed a wide variability in terms of N, lignin and polyphenol concentration in their foliage. Mineralization of N in the foliage of T. candida provenances 02970 and 02971 and T. vogelii provenances 98/04 and 02974 from Malawi occurred rapidly within 14 weeks of incubation. At the end of the 2-year growth period, there was significantly greater total inorganic N under T. candida provenance 02972 (12.5 mg kg⁻¹) than T. vogelii (5 mg kg⁻¹) provenance Mungwi 98/02. Maize (Zea mays L.) yields after T. candida provenances were greater than those after T. vogelii provenances. Further testing of the most promising provenances is needed for their effects on subsequent maize yields under a range of farm conditions. This revised version was published online in June 2006 with corrections to the Cover Date.     

Variation in spring and autumn frost tolerance among provenances of Russian larches (Larix Mill.)

Abstract

Spring and autumn frost tolerance was measured using material from a range-wide (50–67° N, 38–158° E) provenance trial of four Russian larch species (Larix sukaczewii Dyl., L. sibirica Ledeb., L. gmelinii Rupr. and L. cajanderi Mayr.) growing in northern Sweden. Shoots were collected in early May and late September and frozen at ?8, ?12, ?16 and ?20°C. Cambial damage was assessed visually after development under ideal conditions for 2 weeks. Differences in frost damage among provenances were highly significant in both spring and autumn. Autumn frost damage was significantly correlated with provenance latitude and longitude and spring frost damage was significantly correlated with provenance longitude but not latitude. Frost damage was not correlated with provenance elevation. North-western provenances showed the least damage and far-eastern provenances the greatest damage in both spring and autumn. A possible explanation for less spring frost damage to north-western provenances is adaptation to maritime conditions in proximity to the Barents Sea, which is often ice free in late winter. This would counteract early loss of frost tolerance and bud flushing if warm spells occurred in late winter. North-eastern Siberian provenances did not show similar adaptation and may exhibit increased spring frost damage if global warming eventually results in the Arctic Ocean north of Siberia becoming ice free in late winter.     

Pathogenic variation in Cylindrocladium quinqueseptatum causing leaf blight of Eucalyptus1

A wide range of pathogenic variation was observed among the five isolates of Cylindrocladium quinqueseptatum leaf blight (CLB) which could be distinguished as different physiologic strains on 11 differential provenances of Eucalyptus. Susceptibility ranking of different provenances to five isolates also differed significantly indicating differential interaction between isolates and provenances. Analysis of variance showed that CLB severity of a provenance is mainly governed by the genetically different isolates and also that the provenances have closer genetical relationship. The results provide the first evidence for the existence of physiologic strains in C. quinqueseptatum.     

European silver fir (<Emphasis Type="Italic">Abies alba</Emphasis> Mill.) provenances from Calabria,southern Italy: 15-year results from Danish provenance field trials

Height after 15 years, bud burst and mortality varied significantly among 13 southern Italian (Calabrian), a central Italian, a German (Schwarzwald), a Romanian (Carpathian), and a Danish provenance of silver fir (Abies alba Mill.) tested in two field trials in Denmark. The variation in height was especially observed in the field trial that was well protected against late frost in the spring and early frost in the fall by a shelter wood of larch. Provenances from the region of Serra San Bruno (Calabria) and two provenances from the region of Gariglione (Calabria) showed superior height growth at this site compared with the remaining provenances. Height was below average for two provenances from the region of Aspromonte (Calabria). The variation in height correlated significantly with biomasses of the same provenances obtained in early tests. Bud burst was earlier among provenances from the regions of Serra San Bruno and Aspromonte. These were also characterised by poor winter-frost resistance in early tests. The Romanian provenance was not represented in the shelter wood trial. The variation in height between provenances in the other field trial was mainly due to the Romanian and the Danish provenance with superior and poorer growth respectively. Otherwise, differences between the remaining provenances were not significant at this site probably due to the influence of frost. Provenances with poor winter-frost resistance had higher mortality at this site.     

Dry matter production and allocation in Eucalyptus cloeziana and Eucalyptus argophloia seedlings in response to soil water deficits

Effects of soil water availability on seedling growth, dry matter production and allocation were determined for Gympie (humid coastal) and Hungry Hills (dry inland) provenances of Eucalyptus cloeziana F. Muell. and for E. argophloia Blakely (dry inland) species. Seven-month-old seedlings were subjected to well-watered (100% field capacity, FC), moderate (70% FC) and severe (50% FC) soil water regimes in a glasshouse environment for 14 wk. There were significant differences in seedling growth, biomass production and allocation patterns between species. E. argophloia produced twice as much biomass at 100% FC, and more than three times as much at 70% and 50% FC than did either E. cloeziana provenance. Although the humid provenance of E. cloeziana had a greater leaf area at 100% FC conditions than did the dry provenance, total biomass production did not differ significantly. Both E. cloeziana provenances were highly sensitive to water deficits. E. argophloia allocated 10% more biomass to roots than did E. cloeziana. Allometric analyses indicated that relative biomass allocation patterns were significantly affected by genotype but not by soil water availability. These results have implications for taxon selection for cultivation in humid and subhumid regions.     

Ecophysiological and genetic variation in seedling traits and in first-year field performance of eight <Emphasis Type="Italic">Acacia senegal</Emphasis> provenances in the Blue Nile,Sudan

The genetic variation in seed weight, seed number per kg and seedling traits was compared among eight Acacia senegal provenances originating from the clay plain (east) and sand plains (west) of the gum belt in Sudan. The main objective of this study was to identify germplasm sources of A. senegal that have a good seed germination capacity and seedling traits suitable for reforestation in the clay-soil part of the dryland gum belt in the Blue Nile region in Sudan. A specific objective was to tentatively explore the adaptive strategy of A. senegal populations. Seventeen-week-old seedlings were planted in the field at spacing of 3 m × 3 m, giving 100 trees per plot and replication; within a randomized complete block design with four replications. The experimental site was in the clay plain region. Seed variables showed significant differences. Clay plain provenances showed considerable variation in seed weight and seed number. They had the smallest seed weight but the highest seed number, while the sand (western) provenances had the largest seed weight but lowest seed number. Seedling branch number, root length, root to shoot ratio and shoot dry weight differed significantly among the provenances 12 weeks after germination. Clay provenances had the highest branch number and shoot dry weight but the shortest roots and lowest root to shoot ratio. This was interpreted as showing better adaptation to the site in these local provenances in comparison to those originating from the western sandy soil regions. High positive correlations were observed between seedling variables, such as root nodule and branch numbers; this could be used for early selection. The variation was greater between provenance groups than within them, suggesting that especially selection among groups would yield genetic gain.     

低P胁迫对马尾松不同种源根系形态和干物质分配的影响

利用不同地区5个典型马尾松种源，布置3种P水平的盆栽实验，研究马尾松应对低P胁迫时根系形态和干物质分配特征的种源差异。结果表明，P素胁迫的加重导致马尾松干物质积累量的下降和一些根系参数的减小，但植株地下部分的干物质分配量和根系形态参数的相对值却显著增加。低P胁迫下，种源间干物质积累量(包括植株各部分和总的积累量)和侧根数等根系参数差异显著。低P下干物质生产能力较强的福建武平种源对磷肥的敏感性较低，广东信宜和浙江淳安种源次之，类似于大田和水培实验结果。遗传相关分析揭示：侧根发达、须根数量多的种源干物质生产能力强。根体积、侧根数、侧根总长、须根总数等可作为筛选马尾松耐低P种源的有效指标。     

Provenance and family variation in growth performance of Eucalyptus tereticornis (Sm.) in a provenance cum progeny trial in Midnapore, India

Eucalyptus tereticornis Sm. is an important species for agroforestry and commercial plantations in India. Results of a combined provenance–progeny trial of E. tereticornis laid out in 2002 at Midnapore (West Bengal) located in eastern tropical region of India are reported and discussed. Twelve provenances representing 70 families from Australia and Papua New Guinea were evaluated up to the age of 3 years. As a local seed source open-pollinated seed collected from a land race, i.e., Mysore gum (commonly known as Eucalyptus hybrid) was used to serve as check material (control). Significant variation in plant height, clean stem height, girth at breast height (GBH) and field survival was observed due to provenances, as well as families within provenances. This offers an ample scope to a breeder for increasing the growth and productivity in E. tereticornis through selection of provenances and families having potential for higher productivity. Heritability (narrow sense) values were appreciable for growth traits. Within provenance individual tree heritability estimates for height, clean stem length, GBH and number of branches at age 3 years were 0.318, 0.215, 0.269 and 0.231, respectively (assuming a coefficient of relationship of 0.4 for open-pollinated families of E. tereticornis). Provenance of Walsh River, Queensland Australia performed best for plant height, clean stem height, GBH, number of branches and field survival. Apart from this, the provenance from Oro bay to Emo, Papua New Guinea and Burdekin river, Queensland also showed good performance. Provenance from Yurammie, SF from New South Wales performed poorest for growth and survival. Correlations on growth traits were high and statistically significant, indicating that substantial gains could be achieved through indirect selection for one trait based on the direct selection for another. Age–age genetic correlations between age 1 and 3 years for the growth traits were highly significant and positive. Geographic clinal variation pattern was observed as latitude was negatively correlated with height and GBH (P < 0.05); longitude with number of branches (negative, P < 0.05). Fair differences were observed between phenotypic and genotypic coefficient of variability.     

Disease incidence in Eucalyptus microtheca provenances

A provenance trial of Eucalyptus microtheca F. Muell. was studied in order to select resistant provenances against Cytospara eucalypti twig blight, Pestalotiopsis versicolor stem canker and Botryodiplodia theobromae root collar canker. Out of 21 provenances tried, 4 provenances were screened as resistant against diseases and showed best performance.