Legume Tree Species Research Articles

TWO HUNDRED YEARS OF BOTANICAL RECORDS: LEGUMINOSAE TREE SPECIES DIVERSITY IN A BRAZILIAN ATLANTIC FOREST HOTSPOT

The Reserva Biológica do Tinguá (REBIO Tinguá) is a protected area in the state of Rio de Janeiro comprising around 26,000 ha of Brazilian Atlantic Forest. We present an updated floristic inventory of Leguminosae tree species in the REBIO Tinguá. Pre-existing herbarium collections and field expeditions carried out in 2021 and 2022 were used as the basis for (i) assembling a comprehensive taxonomically verified checklist of the legumes, (ii) revealing species distribution patterns across the Submontane (‘tingua_s’) and Montane/High Montane Dense Ombrophilous (‘tingua_ma’) Forest physiognomies of the REBIO Tinguá, and (iii) an UPGMA-based floristic similarity analysis to compare the REBIO Tinguá with 28 other areas of Atlantic Forest in Rio de Janeiro state. Of the total 67 legume tree species identified, 35 are endemic to the Atlantic Forest, six are new occurrences for the area, and seven are listed under different threat categories. The legume-based similarity analysis showed clusters that largely reflect the environmental heterogeneity of the region, where ‘tingua_ma’ is grouped with Macaé de Cima, Mendanha and Santo Aleixo, while ‘tingua_s’ is grouped with Paraty Mirim, Pedra Branca, Poço das Antas, Tijuca and REBIO Union. Our study shows that new records can be made for the REBIO Tinguá, despite it being one of the most thoroughly inventoried areas in the state. Our results reinforce the importance of the REBIO Tinguá for biodiversity conservation, because of its great extent, altitudinal amplitude, and above all, its central position in the state, integrating the Mosaico Central Fluminense and the Tinguá–Bocaina biodiversity corridor.

Productivity of two species of tree legume as sources forage on post-tin mining in Bangka island

Legume tree One of the crops that may function as a viable source of animal feed and be utilized for land reclamation on former mining sites. Ex-tin mining land, which is widely spread in Indonesia, has the potential to transform to productive agricultural land, as long as the land is given sufficient inputs through land rehabilitation. The legume tree has drought resistance, hence limiting its potential for development on many types of land, including post-tin mining areas in the Bangka Tengah District of Bangka Island. The objective of this research is to assess the adaptation of two legume tree species in post-tin mining environments. The research was completed throughout the period from 2017 to 2020. Experiments using Randomized block design (RBD) with two different species of treatments, were repeated a total of five times. Two species tested were (1) Leucaena leucocephala cv Taramba, and (2) Indigofera zollingeriana. Data growth and yield components are harvested every three months and yield is subjected to analysis using the Duncan test at a significance level of 5 %. The research result indicated that all of the tested two species of legume tree were well-adapted to post-tin mining in Bangka Tengah District, Bangka Island. The fresh yield of L.leucocephala cv Taramba was higher (9.1 %) than I.zollingeriana but the quality was similar, so the two species can be developed on post-tin mining areas as forage material for an animal in Central Bangka District, Bangka Island.

Improved crop productivity and soil properties under varying planting densities of Pentaclethra macrophylla Benth. and Acacia auriculiformis A. Cunn. in Congo Basin

Soil fertility depletion is a major constraint to agricultural production in the Congo Basin and is aggravated by climate change. Therefore, agroforestry systems (AFS) are used to improve soil fertility and crop productivity. Indeed, Pentaclethra macrophylla and Acacia auriculiformis are among the most agroforestry species used in this basin. However, smallholders are limited in their choice of agroforestry species and the spacing. Hence, this study comparatively evaluated the effects of P. macrophylla (native) and A. auriculiformis (exotic) legume tree species on soil macronutrients and food crops’ yield during four cropping seasons. To do this, a multifactor trial design was implemented in Lobilo catchment, Congo Basin, with two tree species, four tree planting densities (T1: 2500 trees × ha−1, T2: 625 trees × ha−1, T3: 278 trees × ha−1; and T0: crop monoculture), and three intercrops (cassava, maize, and peanut). The results revealed that both agroforestry species did not significantly differ regarding their impact on soil macronutrients. The total nitrogen and the pH in soil have increased with the cropping seasons. With regard to the food crops, cassava and maize yield were greater under P. macrophylla than under A. auriculiformis. However, the 2500 trees × ha−1 density negatively affected food crops’ yield and did not allow food crop production after the second cropping season. To maximize the positive effects of these AFS, it is essential to plant or co-plant these two agroforestry species at 625 trees × ha−1 density. Future research could investigate other native species and include water and light interactions.

Basal bud banks are the primary determinants of survival in woody legume seedlings after clipping

Disturbances determine the structure of savannas by influencing growth at all stages of a tree's life. Since the seedling stage is such a significant part of a tree's life cycle, greater knowledge of this stage informs woody management and encroachment prevention. In this study, we tested the effect of a suite of seedling functional traits on seedling survival after experimentally-induced disturbance. Twelve mimosoid legume tree species, an important group in African savannas, with different provenances, were grown from seed under experimental conditions. Seedlings were clipped at 1 cm above ground at age 30 days, to simulate disturbance, and their survival recorded. A number of above- and below-ground traits quantifying height, biomass, bud bank and architecture were measured prior to clipping in order to assess what traits could be responsible for post-clipping survival. We also quantified root contraction by calculating the change in height of the lowest bud between the ages of 6 and 60 days. Fire regime and browser biomass of the native range of each species were calculated to test whether these factors predicted seedling survival. Seedling survival was primarily predicted by the whether the plant possessed a bud below 1 cm above ground level, i.e. below the height of clipping. For the first time we report that, in several Vachellia species, root contraction occurred, bringing basal buds closer to the ground, and in some cases below the ground, thus increasing seedling survival after clipping. No environmental variables were significant predictors of survival. Our results suggest that, at this young age, buds close to the soil surface are the most important trait predicting seedling survival, while other traits that are important for saplings and adults do not significantly influence the survival of seedlings. At the seedling stage, herbivory and fire are possibly inflicting the same degree of selection pressures and thus little trait differentiation is evident across the environmental gradient.

Symbiotic bacteria associated with legume tree species in a Mexican tropical dry forest

Symbiotic bacteria associated with legume tree species in a Mexican tropical dry forest

Suitability of selected legume (Vachellia spp.) tree species for forest restoration in the Central Ethiopian highlands

Abstract. Asmelash F, Getachew E. 2022. Suitability of selected legume (Vachellia spp.) tree species for forest restoration in the Central Ethiopian highlands. Nusantara Bioscience 14: 195-202. This study aimed to evaluate the comparative suitability of the legume tree species viz., Vachellia abyssinica (Hochst. ex. Benth.) Kyal. & Boatwr., Vachellia etbaica (Schweinf.) Kyal. & Boatwr., Vachellia lahai (Steud. & Hochst. ex Benth.) Kyal. & Boatwr., and Vachellia seyal (Delile) P.J.H.Hurter for restoring forests in Central Ethiopian highlands. The suitability of three accessions of V. seyal was also compared. The correlation between root nodule number and root Arbuscular Mycorrhizal Fungi (AMF) colonization (RC) and seedlings’ growth variables were computed, and the effect of seedling age on nodule number and RC was determined. Seedlings were grown for nine months on degraded local soil in a mesh house in central Ethiopia. We measured shoot height, shoot fresh weight, rooting depth, root nodule number, and RC in the third and ninth months. The one-way ANOVA results indicated that tree species and/or accession (for V. seyal) had a significant (p<0.05) effect on all the measured variables except shoot height and rooting depth at the ninth month. Generally, nodule number and RC increased with seedling age. However, according to the independent t-test results, significant (p<0.05) differences were recorded for V. abyssinica, with a 57.16% reduction in nodule number, and V. seyal accession-1, with a 418.52% increase in RC. The Spearman’s rank correlation results indicated that the correlation between nodule number and RC was weak and non-significant (p>0.05) both in the third and ninth months. Based on the measured growth variables, nodule number (N-fixation potential), and RC, V. etbaica was the least suitable species for forest restoration in central Ethiopian highlands. The remaining species/accessions are comparably suitable. The V. abyssinica lost its comparative fitness with seedling age, maybe because it is a provenance far away from central Ethiopia. However, V. seyal accession-3, the furthest provenance, has performed much better. The legume trees of Ethiopia are less studied. Their role as environmental engineers could be better understood by knowing more about their root traits. Therefore, this study could motivate future research in this regard. Long-term experiments are required to consider more legume tree species and provenances in the future.

The discovery of a new giant legume tree species in a severely fragmented landscape underscores the alarming threats to the biodiversity of the Brazilian Atlantic Forest

AbstractThe Brazilian Atlantic Forest domain has one of the highest levels of plant species endemism, but the intense historical fragmentation across the coastal Atlantic tropical rain forest has reduced the original vegetation to < 10% and an island-like, patchy landscape. Despite such unprecedented vegetation loss, biogeographically and phylogenetically interesting discoveries in different angiosperm families have been newly reported for the Atlantic Forest in recent years. Here, we show that species discovery in the legume family (Fabaceae) across the Atlantic Forest has counter-intuitively been increasing. Since 1850, more than half of the legume species described for the domain are endemic, and the total number of endemic species has since increased almost four-fold, resulting in the current record of 442 endemic legumes. One such endemic is a new papilionoid legume, only known from a few giant trees that remained misidentified for 70 years since it was first collected. This new species, described here under the name Dipteryx hermetopascoaliana, based on morphological, geographical and molecular evidence, represents the first endemic species to the genus in the Atlantic Forest. We provide a complete morphological description, distribution map, preliminary conservation status and illustration of the new species. The phylogenetic isolation of D. hermetopascoaliana as sister to all other species of the genus and its restricted distribution in a severely fragmented landscape isolated by sugarcane monocultures in north-eastern Brazil are a signature of how critically endangered the biodiversity of the Atlantic Forest is.

The Conservation and Restoration of Riparian Forests along Caribbean Riverbanks Using Legume Trees

In the actual context of global change and biodiversity depletion, soil bioengineering represents an important tool for riparian ecosystem restoration and species conservation. Various techniques have already been implemented, but their adaptation still must be carried out in Caribbean Islands biodiversity hotspots, where suitable species remains unknown. Nitrogen-fixing legumes are particularly relevant for ecological restoration and the diversity of native Caribbean legume trees is promising in the search for suitable species for soil bioengineering. We hypothesized that Caribbean legume tree species present a growth performance and set of biotechnical traits compatible with their use in soil bioengineering. We selected five native legume trees, adapted to riparian environments, in different ecosystems (swamp forest, evergreen seasonal forest, rainforest) based on their ecology, resistance to disturbance and seed production characteristics. We measured root traits relevant for soil bioengineering on nursery grown 3-month-old seedlings. Despite their differences in sensitivity to herbivory and in growth strategies, the selected species have a high potential for use in soil bioengineering, with high seed production, high germination rates—from 88 to 100%—, and 100% survival rates, and are therefore compatible with large scale plant material production. We provided practical guidance tools for their integration into soil bioengineering techniques.

Soil microbial communities of dryland legume plantations are more complex than non-legumes

Soil microorganisms play a crucial role in the vegetation restoration of dryland plantations and participating in biogeochemical cycles. However, how the co-occurrence networks of soil microbial communities respond to dryland legume and non-legume plantations is unclear. Here, we conducted a comparative analysis of legume (13-, 35-, and 55-years Caragana korshinskii) and non-legume (13- and 55-years Platycladus orientalis) plantations, including plant communities, soil physicochemical properties, and soil microbial communities, in the west of the Loess Plateau, China. The results showed higher richness and diversity, more keystone taxa and positive relationships, and larger connectivity and potential functions existed in soil bacterial and fungal communities of legume plantations. Meanwhile, richer plant communities and higher soil nutrients in legume plantations were found than those in non-legume plantations. We revealed that legume plantations shaped a more complex co-occurrence network, forming a virtuous cycling of “plant-soil-microbe” continuum in legume plantation ecosystems. Our results provided a new perspective on evaluating the ecological value and plantation stability of legume tree species in the vegetation restoration engineering of drylands.

Arbuscular mycorrhizal fungi to enhance the growth of tropical endangered species Pterocarpus indicus and Pericopsis mooniana in post gold mine field in Southeast Sulawesi, Indonesia

Abstract. Husna, Tuheteru FD, Arif A. 2021. Arbuscular mycorrhizal fungi to enhance the growth of tropical endangered species Pterocarpus indicus and Pericopsis mooniana in post gold mine field in Southeast Sulawesi, Indonesia. Biodiversitas 22: 3844-3853. Gold mining activities contribute to the national economy, but have a serious impact on forest and environmental degradation and pose a threat to tree species in the tropics. Reforestation of post-gold mining with tropical legume tree species is threatened with extinction. Arbuscular mycorrhizal fungi are effective in conservation of endangered plants and restoration of degraded land. The objective of the study was to evaluate the effect of native AM Fungi inoculation on the growth of Pterocarpus indicus and Pericopsis mooniana in nurseries and post-gold mining fields. P. indicus and P. mooniana seedlings were inoculated with Glomus claroideum Schenk & Smith, Glomus coronatum Giovann., and mixed AMF (G. claroideum, G. coronatum). Uninoculated seedlings were used as control treatment, and they were maintained for 4 months under greenhouse conditions. After 4 months in greenhouse, seedlings were transferred to post-gold mine and planted for 4 months. The percentage of AMF colonization, plant growth, nutrient content and uptake of N, P, K, Fe, Mn were measured after 4 months both in the greenhouse and the field. The percentage of AMF colonization under greenhouse conditions in P. indicus and P. mooniana ranged 5.67-75.3% and 2.2-41.2%. All AMF colonization tended to have higher shoot height, leaf numbers and nodules, plant dry weight and N, P, K content under greenhouse conditions. Shoot height, stem diameter, leaf dry weight, N, P, K, Mn and Fe under field conditions had higher inoculated seedlings than control four months after planting. AMF could be used to conserve endangered tree species in post-gold mining reforestation in the tropics.

Plant genetic barcoding of some Legume tree species grown in Egypt

Plant genetic barcoding of some Legume tree species grown in Egypt

Wood properties and transcriptional responses of poplar hybrids in mixed cropping with the nitrogen-fixing species Robinia pseudoacacia.

Cultivation of fast-growing tree species is often confined to marginal land. Mixed cropping with Robinia pseudoacacia, a legume tree species that forms a symbiosis with N2-fixing bacteria, has been proposed to be a measure to improve soil fertility and to achieve beneficial effects on the cocultivated tree species. The goal of our study was to examine the influence of a Robinia mixture on wood chemistry, anatomy and gene expression in poplar. We hypothesized that annual wood growth is stimulated in species mixtures due to the positive effects of Robinia on nitrogen availability and complementary resource use. Alternatively, we hypothesized that competition, especially for water, has negative effects on the wood growth of poplar. We used two commercial biomass clones, Hybride 275 (H275, Populus trichocarpa×Populus maximowiczii) and Max1 (Populus nigra×P. maximowiczii), which were planted at two locations with contrasting soil fertility in monoculture or mixed plots with Robinia to investigate the annual wood increment, wood nitrogen and δ13C, wood anatomy (length, cell wall thickness, lumina and frequencies of fibers and vessels) and transcriptional profiles in the developing xylem of 4-year-old stems. In a mixture with Robinia, the annual stem increment was reduced, nitrogen in wood was enhanced, δ13C in wood was decreased, vessel and fiber frequencies were increased and fiber lengths and fiber lumina were decreased. Transcriptional profiles showed stronger differences between the genotypes and sites than between mono and mixed cultivation. The transcriptional abundances of only one gene (the putative nitrate transporter, NRT1.2) and one gene ontology term ('immune system process') were significantly enriched in wood-forming tissues in response to the mixture, irrespective of the poplar genotype and growth location. Weighted gene coexpression network analyses extracted gene modules that linked wood nitrogen mainly to vessel traits and wood δ13C with fiber traits. Collectively, molecular and anatomical changes in poplar wood suggest beneficial effects on the water and N supply in response to the mixture with Robinia. These alterations may render poplars less drought-susceptible. However, these benefits are accompanied by a reduced wood increment, emphasizing that other critical factors, presumably light competition or allelopathic effects, overrule a potential growth stimulation.

Butea monosperma: a leguminous species for sustainable forestry programmes

Forestry and greening programs in urban area are faced due to lack of awareness about multiple roles/benefits of trees, especially their role in drought proofing, prevention of soil and water run-off, degraded land restoration, livelihood security and sustainable development. In this regard, Butea monosperma (Lam.) Taubert, a medium-sized legume tree species, has gained much importance because of its multipurpose usage and well adaptability to forestry programs. We have documented the importance of Butea monosperma by surveys and compared with available literature. During the exhaustive surveys, 250 locals were interviewed between 2014 and 2016. We recorded maximum information of Butea monosperma viz. botanical description, traditional knowledge, commercial status, medicinal values and ecological importance. Globally, a reduction in its distribution has categorized it as an endangered species; the main reasons are overexploitation and inadequate awareness. Thus, the present paper deals with the beneficial uses and effectiveness of Butea monosperma for urban forestry and greening which could lead to generate interest in rising demand and value to broaden the scope for conservation, value addition and identification of multipurpose species.

Optimal areas and climate change effects on dragon fruit cultivation in Mesoamerica

AbstractClimbing cacti with edible fruits have been proposed as new dryland fruit crops because their high water-use efficiency reduces water requirement. One lineage of climbers in the cactus family, theHylocereusgroup ofSelenicereus, includes several species that produce edible fruits and is currently cultivated around the world. Fruits are known as pitahayas, pitayas or dragon fruit. Here, by means of ecological niche-based modelling and analytical hierarchical modelling, the optimal areas for cultivating the three main species of this group in Mesoamerica –Selenicereus costaricensis,Selenicereus ocamponisandSelenicereus undatus– are identified. Data on distribution, physiological requirement and host preferences are taken into account to carry out ecological modelling for current and future scenarios of climate and determine its impact on cultivation. Two MIROC climatic future models, one optimistic (ssp216) and a pessimistic (ssp585) were selected and 554 records from Mexico and Central America were gathered. For all three species, temperature and precipitation seasonality, and solar radiation were the most significant variables in the niche modelling. In addition, forS. undatusthe most important hosts, three species of mesquite legume trees were significant to forecast suitable areas for planting. Large areas on the Pacific side from Sinaloa to Costa Rica were predicted as favourable for cultivating the studied three species. Future scenarios of climate change predicted increase of suitable areas for two species and in particular forS. undatusthe increment was the largest. Therefore, dragon fruits are corroborated as promising fruits in view of climate change.

Feldspar Mine Spoil Rehabilitation: Use of Legumes and Bio Inoculants to Establish Soil Fertility on Agro–Silviculture Basis

In recent researches, legumes have been used to revegetate the mining areas with nitrogen-fixing species. The current study also used legumes to revive the fertility of feldspar mine spoil along with Azotobacter chrococcum, Azospirillum brasilense and Glomus mosseae (AMF) in various combinations with organic and inorganic nutrient supplements. All legumes Acacia nilotica, Acacia senegal, Prosopis cineraria, Cyamopsis tetragonoloba and Cassia angustifolia have shown significant enhancement in rhizosphere enzyme activities up to 65%, metabolites up to 51% and nutrient uptake up to 52% whereas, physical growth showed the increment in the range of 10–59% over the uninoculated control. Treatment of Azotobacter+ organic manure+ NPK 50% has been found to enhance maximum growth in most of the parameters significantly, followed by AMF+ organic manure+ NPK50% treatment, while Azospirillum showed its highest impact in enhancing enzyme activities and nitrogen uptake in comparison to Azotobacter and AMF. Legume tree and crop species showed significant response towards the nitrogen fixation thus helped in improving the nutritional value of the mine spoil. Hence, the integrated approach of agro-silviculture practices using legumes and bioinoculants can play a key role in the rehabilitation of feldspar mine spoil.

Cystomyces antheropori, a new rust fungus on Antheroporum glaucum from Thailand

Abstract A rust fungus was found on leaves of Antheroporum glaucum (Fabaceae, Faboideae) in Provinces of Petchaburi and Ratchaburi, western Thailand. No rust fungus was previously reported on this legume tree species. The new rust fungus was apparently microcyclic, producing telia surrounding dense aggregates of spermogonia, on the abaxial leaf surface. Teliospores were produced by sympodial proliferation from a basal sporogenous cell and mostly composed of three fertile cells subtended by two hygroscopic cysts. A germ slit was present near the septum in two of three fertile cells. A simple persistent pedicel was attached to the teliospore cysts. Because of resemblance in the teliospore morphology, this fungus was compared to Bibulocystis, Caetea, Cystomyces, and Spumula. Radially symmetric teliospores in the horizontal plane with three more or less globose fertile cells subtended by two hygroscopic cysts and the presence of a germ slit near the septum in fertile cells are the characteristics of the genus Cystomyces. Therefore, it was concluded that the fungus should be classified in Cystomyces, and a new name, C. antheropori was proposed.

Effects of mechanical and acid scarification on germination performance of Schizolobium parahyba (Fabaceae – Caesalpinioideae) seeds

Improving seed germination of native species is fundamental for assisting restoration practices, particular in highly degraded ecosystems such as tropical moist forests. Tropical moist forests of Central and South America continue to decrease as a result of fragmentation and conversion of forested land to agriculture. Schizolobium parahyba is a pioneer legume tree species widely used in restoration practices due to its fast growth rate, nitrogen-fixing capacity, and wood properties. Seeds of this species exhibit low germination as a result of physical dormancy, which highly limits its propagation on a large scale. We evaluated the effects of mechanical and acid scarification treatments with solutions of sulfuric (10%, 20%) and chloridric (25%, 50%, 75%) on Schizolobium parahyba seed germination. Mechanically scarified seeds had higher germination percentage (92.5%) than seeds treated with chloridric acid (50%), sulfuric acid (33.13±.2.11%) or intact seeds (17.5%). Seeds soaked in 10% sulfuric acid for 1 and 5 minutes exhibited higher germination values than seeds soaked in 20% for 10 minutes. Seeds soaked in 75% and 50% chloridric acid solutions for 5 and 10 minutes had an overall higher and faster germination than seeds soaked in 25% for 1 minute. This study indicates that mechanical scarification and acid scarification with solutions of chloridric acid solutions of 50% and 75% can highly improve large-scale propagation of S.parahyba and thus assist habitat restoration and conservation practices in degraded moist tropical forests.

Evaluating Soil Organic Carbon Sequestration Potential of Tree Species in Subtropical and Humid forest of Brahmaputra Valley, Assam

Soil organic carbon sequestration potential of different tree was analyzed in every year. Five years after plantation average soil organic carbon was recorded highest under fast growing non legume trees (1.82 %) followed by medium growing (1.72 %) and then slow growing (1.60 %). SOC sequestration potential of legume tree species was significantly lower. It was 1.80 % under fast growing legumes, 1.58 % in medium growing and 1.55 % in slow growing legume trees. On individual comparison of non legume trees, Anthocephalus chinensis found to sequester more (1.98%) carbon as soil organic carbon followed by Trewia nudiflora (1.66%), Alstonia scholaris (1.62%) and Lagerstroemia.speciosa (1.57%). Lowest soil organic carbon sequestration was found under Chukrasia. tabularis (1.26%). No significant difference was observed in SOC sequestration potential between Dipterocarpus retusus, Artocarpus chaplasha, Ficus hispida, Mallotus albus, Litsea nitida, Castanopsis indica, Taphrosia candida, Albizzia procera and A. lebbek.

Exploratory Studies on Occurrence and Potential Benefits of High Fruit Yielding Reproductive Phenophasic Variants of Pithecellobium dulce in Augmenting Fruit Based Semi-arid Agro Forestry Systems

Background: Pithecellobium dulce is a multipurpose legume tree species of high ecological significance. Several reports indicate existence of huge genetic diversity within the natural population of the species. Various morphological parameters have been used to assess intra species genetic diversity, however, there is no report available so far on diversities in reproductive phenology of P. dulce of semi-arid or arid climate.
 Methods: The present paper is based on assessment of diversity in flowering phenophases through construction of phenological calendar incorporating temporally observable morpho-phenotypic descriptors for reproductive behaviour of individual trees comprising natural population of the species at designated study sites during a period of three years. The study was carried out during September, 2015 and March, 2019 at Ajmer, Rajasthan, India. Data were periodically obtained and statistically analyzed.
 Results: Majority of trees of flowering stage (89.94%) exhibited normal or winter blooms in which flowering was initiated in almost synchronized manner during December; 10.05% of normal blooming trees inconsistently showed additional early or autumn blooms during either September or October or November; 2.58% of trees exhibited early blooms in which flowering was consistently initiated in the month of September in addition to normal blooms. The overall production and availability of fresh fruits in early-cum-normal episodic blooming trees were greater as compared to only normal blooming trees. Though, the numerical fruit productivity in winter blooms was superior to autumn, the pomometric characteristics were inferior in former in early-cum-normal episodic blooming trees.
 Conclusion: The methodology is a novel experimental approach to assess diversities in reproductive phenology of seed raised population of high value fruit bearing economically important tree species. The present work explores agronomically valuable variants of P. dulce and also reports causes of appearance of persistent fruits and sporadic in-situ germination of seeds. Based on above findings, the paper also makes evolutionary predictions that how a shift in flowering phenology of P. dulce as exhibited by the elite variants could have long-term implications for reshaping of future landscapes of semi-arid or arid climate. Conclusively, Winter to autumn phenophasic shift in flowering in P. dulce is economically productive, evolutionarily progressive, and environmentally well cued partial retrieval under semi-arid conditions. Moreover, the phenophasic variants could serve as candidate plus trees that deserve out of the season floral management and clonal propagation, thereby the species may get a fillip to status up gradation from minor fruits to major fruit category.

Seed germination of a South American forest tree described by linear thermal time models

Thermal time models may describe and compare seed germination, providing information useful to explain species distribution. However, the capacity of such threshold models to describe germination of tropical native species has been less studied. We evaluated seed germination of a legume tree species (Peltophorum dubium), typical from South American seasonal forests, as described by two linear thermal time models: probit model and graphic model. Seeds were provided from four different provenances in a latitudinal gradient in Brazil, and their physical dormancy mechanically released before the trials. Graphic model and probit regression were used to determine thermal parameters (cardinal temperatures and thermal time requirement) on sub- and supra-optimal ranges for the different seed provenances. Germination rate mainly followed linear relationship with temperature, and regression lines of different germination fractions converged base temperature in the x-axis. Therefore, probit model assumed a single-value of base temperature in the sub-optimal range and a normal distribution of thermal time. Base temperature tended to be higher in the Northern provenance, Porto Velho, showing slower germination under cooler temperatures. Supra-optimal temperatures have shown similar thermal time requirements and different values for ceiling temperature, according to model predictions. No clear patterns have been found between seed provenances and thermal time requirement. Both probit and graphic models have provided reasonable predictions of germination times (t10 and t50), except under the coolest temperatures. Probit regression always described at least 70% of seed germination. Thermal time assumptions, linear models applicability and their limitations are discussed.