Performance of carrot and onion seed primed with beneficial microorganisms in glasshouse and field trials

Beneficial microorganisms (Clonostachys rosea IK726, Pseudomonas chlororaphis MA342, Pseudomonas fluorescens CHA0, Trichoderma harzianum T22 and Trichoderma viride S17a) were successfully applied to carrot and onion seed during a commercial drum priming process. Applied microorganisms were recovered above the target of at least 1 × 10⁵ cfu g⁻¹ seed following subsequent application of pesticides to the seed according to standard commercial practices of film-coating carrot and pelletting onion seed. Two glasshouse experiments consistently showed that priming improved emergence of carrot seed and that C. rosea IK726 further improved emergence time. Priming improved emergence of onion seed in one glasshouse experiment, but had an unexpected negative effect on emergence in the second experiment, possibly due to the proliferation of an unidentified indigenous microorganism during priming, becoming deleterious in high numbers. In this experiment, the application of beneficial microorganisms during priming negated this effect and significantly improved emergence. For each crop, a series of field trials was also carried out over three years, at two different sites each year. Although some positive effects of different seed treatments were seen on emergence or yield in individual field trials, no consistent effects were found for primed or microorganism-treated seed across all sites and years. However, a combined analysis of data for all years and sites indicated that pesticide application did consistently improve emergence and yield for both carrot and onion. This is the first comprehensive study assessing glasshouse and field performance of carrot and onion seed primed with beneficial microorganisms during a commercial process of drum priming in the UK.     

Beneficial microorganism survival on seed, roots and in rhizosphere soil following application to seed during drum priming

Priming is a technique used to improve seedling establishment of direct-seeded crops such as onion and carrot, resulting in a quick and uniform emergence. This work investigated the application of four selected beneficial microorganisms (Pseudomonas chlororaphis MA342, Pseudomonas fluorescens CHA0, Clonostachys rosea IK726d11 and Trichoderma harzianum T22) to onion and carrot seed during drum priming, and their subsequent survival and establishment in the rhizosphere once the seed was planted. Different application rates of fungi (7 log₁₀ cfu g⁻¹ dry seed) and bacteria (6 log₁₀ cfu g⁻¹ dry seed) were required on onion to achieve the end target of 5 log₁₀ cfu g⁻¹ dry seed, whereas a lower rate (5 log₁₀ cfu g⁻¹ dry seed for both bacteria and fungi) was successful on carrot. Microorganism-treated seed was planted in soil in the glasshouse and root and rhizosphere soil samples were taken at 2, 4 and 8 weeks post-planting. All seed-applied microorganisms were recovered throughout the experiment, although differences in the survival patterns were seen. The bacterial isolates declined in number over time, with P. fluorescens CHA0 showing better overall survival than P. chlororaphis MA342, particularly on the roots and in the rhizosphere soil of carrot. In contrast to the bacteria, the fungal isolate C. rosea IK726d11 showed good survival on both onion and carrot, and increased significantly in number throughout the 8-week period. Trichoderma harzianum T22 remained relatively constant in number throughout the experiment, but showed better survival on carrot than onion roots. Similar results were found in three different soil-types.     

Changes in Levels and Integrity of Ribosomal RNA During Seed Maturation and Germination in Carrot (Daucus carota L.)

Thompson, S., Bryant, J. A. and Brocklehurst, P. A. 1987. Changesin levels and integrity of ribosomal RNA during seed maturationand germination in carrot (Daucus carota L.).—J. exp.Bot. 38: 1343–1350. Amounts and integrity (percentage of complete un-nicked molecules)of ribosomal RNA (rRNA) during germination in carrot seed lotsof differing vigour and viability were examined using aqueousand formamide gel electrophoresis. In unaged seed, amounts ofrRNA per seed in dry seed are not related to maturity, vigouror viability. However, rRNA in immature seed is more vulnerableto damage by ageing than rRNA in mature seed; thus, amountsof rRNA per seed in aged seed are indicators of vigour and viability.On imbibition of aged or unaged seed, more rRNA fragmentationoccurs in immature seed than in mature seed, and the time atwhich the effects of synthesis outweigh the effects of degradationis earlier during germination in mature than in immature seed. Key words: rRNA, seed maturation, seed germination, Daucus carota L.     

Application of Beneficial Microorganisms to Seeds during Drum Priming

Five microbial plant growth promoters or biocontrol agents (Pseudomonas fluorescens CHA0, Pseudomonas sp. AB842, Bacillus subtilis MBI600, Trichoderma harzianum T22 and T. virens G20) were assessed for ability to proliferate on seeds of carrot, parsnip and leek. In small-scale priming systems, both pseudomonads and MBI600 (when applied as cells) at levels between 10⁵ and 10⁶ cfu g^?1 seed were able to colonise all seeds at the end of priming (240 h) despite initial poor recovery after addition of the cells in some cases. Pf CHA0 was a particularly aggressive seed coloniser often comprising the total pseudomonad population at the end of priming. Drying the seed after priming resulted in <1 log₁₀ cfu g^?1 seed loss for the pseudomonads but greater losses for MBI600 on carrot and leek seed. Application of spores of MBI600 resulted in little loss in cfu g^?1 seed following addition of the cells and these levels were maintained throughout the priming period and after drying back. Both T22 and G20 were recovered from carrot and parsnip at the end of priming and in general reflected survival of the inoculum rather than proliferation. T22 and G20 could not be recovered from leek seed following priming. Comparisons were made between proliferation and survival in large-scale drum priming with post-priming application of microorganisms. Pf CHA0 proliferated on carrot and parsnip seed during drum priming and survived the drying back process whereas there was no recovery when applied as a post-priming treatment. In contrast, MBI600 could not be recovered when applied during priming as cells, whereas recovery was good when applied post-priming as spores. T22 spores could be applied in either manner. Post-priming application of metalaxyl and thiabendazole had variable effects on microorganism recovery. The significance of the application of microorganisms to seeds during priming is discussed.     

Chemical,physical and biological control of carrot seedling diseases

In naturally infested soil containingPythium ultimum, P. acanthicum andPhytophthora megasperma, onlyP. ultimum was associated with root rot and damped-off seedlings. Damping-off was promoted by low soil temperatures and by flooding. Seedling stands were markedly reduced when seed was pre-incubated in soil at 12°C but not at 25°C or 35°C. Dusting carrot seed with metalaxyl significantly increased seedling stands in the field at rates from 1.5–6 g kg⁻¹ seed and in both flooded and unflooded, naturally infested soil at 3.15 g kg⁻¹. In greenhouse experiments using artifically infested soil,P. ultimum andP. paroecandrum caused damping-off of carrot seedlings andRhizoctonia solani reduced root and shoot weights.R. solani caused damping-off in nutrient-enriched soil.P. acanthicum andP. megasperma were not pathogenic to seedlings, although both fungi colonized roots. Soil populations of allPythium spp., particularlyP. ultimum, increased during growth of seedlings and population growth ofP. megasperma was promoted by periodic flooding. Infestation of soil withP. acanthicum did not reduce damping-off of carrot seedlings byP. ultimum orP. paroecandrum, but significantly increased root and shoot weights and decreased root colonization byR. solani P. acanthicum has potential as a biocontrol agent againstR. solani.     

Genebank biodiversity assessments regarding optimal sample size and seed harvesting techniques for the regeneration of carrot accessions

Small, finite populations are particularly vulnerable to diversity loss during regeneration. The regeneration of a highly outbreeding open-pollinated variety relies on estimated effective population size, via the measurement of temporal change in allele frequencies. Using appropriate estimators for dominant gene markers, effective sizes were calculated for five sizes of a mating population and two seed harvesting procedures. We have shown that, in the case of carrot regeneration, 70 equally harvested plants should provide an effective size (N _e) of at least 50 plants. This value seems sufficient to limit genetic drift and to preserve an efficient level of genetic diversity within the collection. The efficiency of balanced samples (made of an equal number of seeds per plant) is compared to that of bulk samples (seeds randomly chosen among the total seed lot coming from all the plants).     

Effect of distance,aggregation, and habitat on levels of seed predation for two mammal — dispersed neotropical rain forest tree species

The effect of seed aggregation and distance from conspecific trees on seed predation was experimentally examined for two neotropical tree species, Macoubea guianensis (Apocynaceae) and Pouteria sp. (Sapotaceae) in a lowland tropical rain forest in northeastern Peru. Results of these experiments are discussed in the context of the Janzen-Connell model (Janzen 1970; Connell 1971), which predicts decreased seed survival near parent trees due to either density-or distance-responsive mortality, and Howe's model (Howe 1989) which predicts that trees with seeds dispersed in clumps (aggregated) will not suffer density-dependent predation, and will have higher survival of seeds near the parent tree than other trees. We also examined whether predation on seeds of these species was affected by seed placement in or near 30-m-wide strips regenerating after clear-cutting. Both species appeared to be mammal-dispersed but differed in how frugivores handled seeds, seed size, overall fruit crop size, and gemination time. Neither of the two species studied appeared to suffer seed predation in a manner predicted by the Janzen-Connell model, and patterns of seed predation for only one of the species was similar to predictions of Howe's model. For neither species did seed predation along the edge of, or in the center of, regenerating clear cuts differ from predation 15 m into the primary forest. For Pouteria, seed predation in and near regnerating strips was significantly greater than around forest trees, but the opposite pattern held for Macoubea. Overall, seed predation was much greater on Macoubea. The difference in seed predation for these two species was most likely a result of differences in the types of seed predators that attacked these two species.     

Seed mass,genotype, and density effects on growth and yield of Oenothera biennis L.

Summary Seed mass and genotypic effects on the growth and reproduction of Oenothera biennis L. over a gradient of intraspecific density were examined in a greenhouse experiment. By using genetically identical seeds from five parental genotypes we were able to examine independently the effects of seed mass and genotype on seedling and adult performance. Seedling size was significantly correlated with seed mass for the first five weeks but had no effect on adult size or reproductive output. In contrast, genotype differences became increasingly apparent with time. In particular, there were striking differences in reproductive output among genotypes. Plants grown from two of the genotypes consistently produced more, but lighter, seeds and a greater proportion flowered at high density than the other three genotypes. In all five genotypes, seed number was much more variable than seed mass across the density gradient. Initial seed mass accounted for a significant proportion of the variation in progeny seed mass, and mean seed mass produced in the greenhouse was positively correlated with mean seed mass of the parent (in the field). This result, together with the observed constancy of seed mass within a genotype across the density gradient, indicates the differences in reproductive output among these genotypes are genetically determined.     

Laboratory rearing ofAnaphes sordidatus [Hym.: Mymaridae] on carrot weevil eggs [Col.: Curculionidae]

A technique for rearingAnaphes sordidatus (Girault) on eggs of laboratory-reared carrot weevil,Listronotus oregonensis (Le Conte), is described. Individual rearing was possible by using polyethylene embedding capsules that enabled easy manipulation of parasitized carrot weevil eggs for use in subsequent experimental procedures. The technique described resulted in 65% parasitization of carrot weevil eggs and 90 mn per day were sufficient to obtainca. 200 parasites daily.      

Seed size selection by olive baboons

Seed size is an important plant fitness trait that can influence several steps between fruiting and the establishment of a plant’s offspring. Seed size varies considerably within many plant species, yet the relevance of the trait for intra-specific fruit choice by primates has received little attention. Primates may select certain seed sizes within a species for a number of reasons, e.g. to decrease indigestible seed load or increase pulp intake per fruit. Olive baboons (Papio anubis, Cercopithecidae) are known to select seed size in unripe and mature pods of Parkia biglobosa (Mimosaceae) differentially, so that pods with small seeds, and an intermediate seed number, contribute most to dispersal by baboons. We tested whether olive baboons likewise select for smaller ripe seeds within each of nine additional fruit species whose fruit pulp baboons commonly consume, and for larger seeds in one species in which baboons feed on the seeds. Species differed in fruit type and seed number per fruit. For five of these species, baboons dispersed seeds that were significantly smaller than seeds extracted manually from randomly collected fresh fruits. In contrast, for three species, baboons swallowed seeds that were significantly longer and/or wider than seeds from fresh fruits. In two species, sizes of ingested seeds and seeds from fresh fruits did not differ significantly. Baboons frequently spat out seeds of Drypetes floribunda (Euphorbiaceae) but not those of other plant species having seeds of equal size. Oral processing of D. floribunda seeds depended on seed size: seeds that were spat out were significantly larger and swallowed seeds smaller, than seeds from randomly collected fresh fruits. We argue that seed size selection in baboons is influenced, among other traits, by the amount of pulp rewarded per fruit relative to seed load, which is likely to vary with fruit and seed shape.     

Satiation of predispersal seed predators: the importance of considering both plant and seed levels

Plants can reduce the fitness costs of granivory by satiating seed predators. The most common satiation mechanism is the production of large crops, which ensures that a proportion of the seeds survive predation. Nevertheless, satiation of small granivores at the seed level may also exist. Larger seeds would satiate more efficiently, enhancing the probability of seed survival after having been attacked. However, a larger seed size could compromise the efficiency of satiation by means of large crops if there were a negative relationship between seed size and the number of seeds produced by an individual plant. We analyze both types of satiation in the interaction between the holm oak Quercus ilex and the chestnut weevil Curculio elephas. Both crop size and acorn size differed strongly in a sample of 32 trees. Larger crop sizes satiated weevils, and higher proportions of the seeds were not attacked as crop size increased. Larger seeds also satiated weevil larvae, as a larger acorn size increased the likelihood of embryo survival. Seedling size was strongly related to acorn size and was reduced by weevil attack, but seedlings coming from large weeviled acorns were still larger. The number and the size of the acorns produced by individual trees were negatively related. Larger proportions of the crop were infested in oaks producing less numerous crops of larger acorns. However, contrary to expectations, these trees did not satiate more effectively at the seed level either. Effective satiation by larger acorns was precluded by larger multi-infestation rates associated to smaller seed crops, in such a way that the proportion of attacked seeds that survived did not vary among trees with different acorn sizes. These results highlight the need of considering satiation by means of large crops and large seeds in studies of predispersal seed predation. Long-term monitoring on individual oaks will help to assess whether there is a trade-off between the number and the size of the acorns and, if it existed, how it could condition the fitness consequences of both types of satiation.     

Germintion,nodulation and early growth response of a hard-seeded legume,Lathyrus sylvestris L. (flatpea)

Summary Flatpea (Lathyrus sylvestris L.) requires seed scarification for rapid germination and specificRhizobium leguminosarum strain for nodulation. Methods of inoculation were investigated to determine which would be effective for at least two weeks after seeding. Application of powdered peat to wet seeds was inadequate. Lime pelleting and granular soil implants were effective inoculants, but there appears to be a different advantage to seedling for earch metod. Granular soil implant caused nodulation to a greater depth on the tap root, and lime pelleting caused plants to exhibit higher acetylene reduction activity.     

Mast-seeding in the cycad genus Encephalartos: a test of the predator satiation hypothesis

Mast-seeding behaviour was monitored in 18 populations of eight species of the African cycad genus Encephalartos between 1988 and 1991. The coefficient of variation (V) in annual cone production for each population ranged between 88 and 200, indicating large fluctuations in reproductive effort between years. Data were collected to determine whether mast-seeding reduced levels of predispersal seed predation by satiating seed predators in mast years and whether it resulted in a reproductive advantage over plants which reproduced more frequently. Masting intensity was greatest in those populations in which individual plants suffered the highest levels of predispersal seed predation in years when only a few plants produced seeds. The principal seed predators were two congeneric weevil species, Antliarhinus zamiae and A. signatus, which develop exclusively on cycad seeds. The lowest intensity of mast-seeding was recorded for cycad populations with low levels of seed predation and in which A. zamiae and A. signatus occurred only in low numbers or were entirely absent. Larger seed crops appeared to result in lower levels of seed predation by A. zamiae and A. signatus in four populations of E. altensteinii, and differences in seed crop size accounted for 48–66% of variation in levels of seed predation in populations of five cycad species. In one population of E. altensteinii, lower levels of seed predation in plants reproducing periodically resulted in a reproductive advantage over plants reproducing more frequently. These results are consistent with the predator satiation hypothesis. However, in most cycad populations, numbers of seed predators did not appear to decrease significantly after a period of 2–8 years between reproductive episodes and, in two of three populations examined, periodic reproduction did not increase the number of seeds surviving to dispersal over a 4-year period. These results are interpreted to mean that periodic reproduction has not evolved in response to selection imposed by seed predators, but that selection may favour those plants which experience lower levels of seed predation by coning in synchrony with the majority of plants in the population.     

Aggregated seed dispersal by wreathed hornbills at a roost site in a moist evergreen forest of Thailand

Hornbills (Bucerotidae) are widely regarded as important seed dispersers in tropical forests in Africa and Asia. We investigated how the roosting behavior of wreathed hornbills (Aceros undulatus) influences seed deposition and seedling survival at a roost site in a moist evergreen forest of Khao Yai National Park, Thailand. Fallen fruits and seeds were collected in traps that were placed around a roosting site for 14 months, and seedlings were monitored in adjacent quadrats for 3 years. Seedfall and seedlings of species represented in the hornbill diet occurred at significantly higher densities in the traps and quadrats located beneath the crown of the roosting tree than in those located beyond the crown. With the exception of Cinnamomum subavenium, the seeds and seedlings of most diet species rarely survived beyond the first year. The quality of hornbill dispersal to this roosting site may be poor due to the highly concentrated seedfall, which results in high seed and seedling mortality. However, the number of seeds deposited by each hornbill each day at roosting sites is relatively low. Wreathed hornbills are primarily scatter dispersers during the day and probably serve as agents of seed dispersal in the moist evergreen forest of Khao Yai.     

Embryogenesis and seed development in Sinomanglietia glauca (Magnoliaceae)

The development of the floral bud, especially the ovule and seed coat, of Sinomanglietia glauca was observed. Floral buds were covered by eight to nine hypsophyll pieces. The hypsophyll nearest the tepal was closed completely and characterized by two arrays of densely stained cells with dense cytoplasm, which split longitudinally at flowering. The perianth consisted of 16 tepals arranged in three whorls. The gynoecium was composed of numerous apocarpous carpels; the ovule was anatropous with two integuments. Embryogenesis was of the Polygonum type, and the endosperm was nuclear. The inner integument degenerated during seed development. The seed of S. glauca had an endotestal seed coat comprised of a sclerotic layer derived from the inner adaxial epidermis of the outer integument and a sarcotesta derived mainly from the middle cells between the inner and outer epidermis of the outer integument. The embryo developed normally, so embryogenesis is not the cause of difficult regeneration.     

星油藤蒴果及种子的性状变异研究

为进行星油藤(Plukenetia volubilis L.)良种选育,对其蒴果和种子的性状变异进行了研究。结果表明,星油藤蒴果中4、5、6裂片果分别为49.71%、37.69%和12.60%,以4和5裂片为主;种子性状变异系数比果实的小,种子性状比果实更稳定。按果裂片类型统计,以4裂片的性状变异系数最小,性状也较为稳定,性状分化变异率有54.19%~95.63%来自蒴果间,而果实和种子性状分化变异率分别有79.81%~95.76%和67.66%~93.0%来源于裂片类型,性状分化变异受裂片数影响大,而相同裂片数不同蒴果间的变异程度低。不同裂片类型的果实与种子大多数性状间均存在显著或极显著差异,果裂数是造成性状差异的主要原因。种子萌发率以6裂片果5裂片果4裂片果,平均萌发率超过91%;种子萌发率与单果重、单果重与果形态指标、种子重与种子形态性状间均存在极显著正相关关系,其中单果重对果厚、种子重对种子宽的影响大于其它性状。综合分析星油藤以4裂片果的生物产量最高,平均果重和种子重均好于其他类型。     

Seed coat anatomy ofCrossostylis (Rhizophoraceae): its evolutionary and systematic implications

The seed coat structure of all 13 species ofCrossostylis was studied to contribute to an understanding of species delimitation and relationships within the genus. The mature seed coat is relatively uniform and consistently constructed mainly by a well-developed exotesta and a well-developed fibrous exotegmen. The species differ in the thickness of the exotesta and exotegmen, the anatomy of exotestal cells, the presence and absence of persistent mesotesta, and so forth. On the basis of comparisons of these characters, close relationships are suggested in the species groups such as:Crossostylis banksiana andC. cominsii; C. biflora, C. raiateensis andC. multiflora; C. gandiflora, C. sebertii andC. imera; and five species in the Fiji Islands. These relationships except for those of Fijian five species are also supported by cladistics as their common characters are evaluated as synapomorphy. Species-level separation ofC. banksiana, C. pedunculata andC. raiateensis each from the closest species is doubted based on the results of seed coat structure.     

Allometric allocation in fruit and seed packaging conditions the conflict among selective pressures on seed size

Selective pressures on seed size could vary among the different stages of plant life cycles, so no simple relation could explain a priori its evolution. Here, we determined the relationships between seed size and two fitness components—seed dispersal and survival from predation—in a bird-dispersed tree, Crataegus monogyna. We interpret these relationships in relation to the patterns of mass allocation to fruit and seed components. Selection patterns were assessed at two levels (1) selection pressures on the parent tree; comparing seed dispersal efficiency among individual plants and (2) selection pressures at the individual seed level; comparing seed size variation (i) before and after dispersal, and (ii) before and after postdispersal seed predation. Dispersal efficiency (percentage of seed crop dispersed) was positively correlated with fruit mass and fruit width. Differences in crop size did not offset this effect, and larger seeds were overrepresented in the seed rain relative to the seed pool before dispersal. However, the advantage of larger seeds during the dispersal stage was cancelled later by an opposite selection pressure exerted by seed predators. As a result, smaller seeds had a higher probability of surviving postdispersal seed predation, establishing an evolutionary conflict imposed by the need for dispersal and the danger of being predated. Birds and rodents preferentially selected highly profitable fruits and seeds in terms of the relative proportion of their components. Larger fruits had a higher pulp to seed proportion than smaller ones, and all seeds had the same proportion of coat relative to the embryo-plus-endosperm fraction. Hence, although predator pressures were stronger than disperser ones, larger seeds invested proportionally less in structural defense than in dispersal.     

Initial effects of experimental warming on carbon exchange rates, plant growth and microbial dynamics of a lichen-rich dwarf shrub tundra in Siberia

Biological soil crusts can affect seed germination and seedling establishment. We have investigated the effect of biological soil crusts on seed water status as a potential mechanism affecting seed germination. The seed water potential of two annual grasses, one exotic Bromus tectorum L. and another native Vulpia microstachys Nutt., were analyzed after placing the seeds on bare soil, on a crust that contains various lichens and mosses (mixed crust), or on a crust dominated by the crustose lichen Diploschistes muscorum (Scop.) R. Sant. (Diploschistes crust). Seed water potential and germination were similar on the bare soil and the mixed crust, except for the initial germination of V. microstachys, which was higher on the mixed crust than on the bare soil. For the two grasses studied, seed water potential was significantly higher on the bare soil and mixed crust than on the Diploschistes crust. These differences in water potential correlated with differences in germination, which was much lower on the lichen crust. Experiments were conducted under two watering regimens. Increasing the frequency of watering amplified the differences in seed water potential and germination between the Diploschistes crust and the other two surfaces. For a particular watering regimen, the bare soil, mixed crust, and Diploschistes crust received the same amount of water, but they reached significantly different water potentials. Throughout the experiments, the water potential of the soil and mixed crust remained above −0.6 MPa, while there was a marked decline in the water potential of the Diploschistes surface to about −4 MPa. To ascertain that water was the major factor limiting germination on the Diploschistes crust, we conducted germination tests in an environment with 100% relative humidity. Under these conditions, germination on the Diploschistes crust was similar to that on the bare soil. However, the seeds that germinated on the Diploschistes crust did not penetrate this surface and approximately 60% of their root tips became necrotic. Our results indicate that the presence of D. muscorum can inhibit seedling establishment by two mechanisms: a reduction in seed water absorption and an increase in root tip mortality.     

金沙江干热河谷滇榄仁种子扩散与种子库特征研究

采用随机取样和跟踪调查的方法对滇榄仁(Terminalia franchetii)种子扩散规律、空间分布特征以及种子库动态进行了系统研究。结果表明,滇榄仁种子扩散受到较强的风力作用影响,具有明显的方向性,扩散距离是其树高的1.6倍以上。不同群落类型中,滇榄仁的土壤种子库存在较大差异,但不同时间段的变化趋势基本一致,即在雨季(6月、8月和10月)数量相对较少,12月到翌年4月,数量逐渐增加。滇榄仁植冠种子库从当年10月开始缓慢脱落,到翌年3月达到脱落高峰(15%以上种子此时脱落),然后再次进入缓慢脱落期,翌年6、7月的种子脱落速率最低,但直到翌年10月仍有部分种子(约15%左右)存在于植株冠层。总体来说,不同类型群落中,滇榄仁幼苗更新不良的原因不应是缺乏种源,可能与种子质量以及群落环境等影响群落天然更新的其它因子存在较大关联。同时,滇榄仁土壤种子库数量与植冠种子库的脱落过程存在紧密联系,而植冠种子脱落可能与该区域气候因子存在着较大依存关系,其中,与风力可能存在着正相关,与降雨量和空气相对湿度存在着负相关,这可能是滇榄仁长期以来对干热河谷环境的一种适应特征。