Prediction of survival of Pinus radiata seedlings subjected to physical-water restriction extreme using learning neural networks

Drought is one of the main environmental factors that limit plant growth. For this reason, it is necessary to apply nursery cultural practices to produce quality seedlings for successful reforestation in drought- prone sites. In this study, the extreme learning machines and multilayer are applied to predict survival in 5-month-old Pinus radiataseedlings belonging to 98 families of a genetic improvement program and subjected to a period of water restriction in the nursery. After applying the water restriction, survival was registered in each seedling as a categorical variable (1 = alive seedling, 0 = dead seedling). Additionally, the following morphological attributes of each seedling were also measured: total height, root collar diameter, slenderness index, dry weight of needles, stems and roots, total dry weight, and the root to shoot ratio. The extreme learning machines predicted with a better rate the survival of the “alive” class compared to the “dead” class. On the other hand, the multilayer-extreme learning machines improved the precision of survival concerning the class of “dead” seedlings. According to the results of the model, an overall precision of 74% was obtained. This may be due to the great genetic variability presented by each of the Pinus radiatafamily used in the database. However, this technique allowed predicting the survival of a group of seedlings grown in the nursery, which can be a tool to support the selection process of high quality planting stock.

Impacts D’une Technique De Restauration De Terre Dégradée Sur La Survie Et La Croissance Des Plants De Quatre Espèces De Combretaceae En Zone Sahélienne Du Niger

Les banquettes sylvopastorales constituent l’une des techniques les plus utilisées au Niger pour restaurer les terres dégradées de plateaux. La présente expérimentation a été réalisée sur un plateau dégradé de Simiri dans l’Ouest nigérien où des banquettes sylvopastorales ont été installées. L’objectif est d’évaluer la survie et la croissance des plants de quatre essences locales de Combretaceae, Combretum glutinosum, Combretum micranthum, Combretum nigricans et Guiera senegalensis. Les méthodes utilisées ont consisté d’abord à délimiter un espace sur le plateau dégradé où 40 banquettes sont confectionnées et un autre espace sans banquette pour servir de témoin. Dans les banquettes, 200 plants de chaque espèce ont été plantés à raison de 20 plants/banquette. Deux mois après la plantation un suivi périodique de l’humidité du sol et des paramètres dendrométriques des plants a été effectué durant 30 mois. Les paramètres dendrométriques mesurés sont le taux de survie, la hauteur et le diamètre au collet du grand axe caulinaire, le nombre de rejets et de feuilles. Les résultats obtenus ont montré d’une part que les banquettes améliorent les conditions hydriques du sol de 18,19 % par rapport à la zone non traitée (sans banquette) et d’autre part que les meilleurs taux de survie et de croissance ont été observés au niveau des espèces Guiera senegalensis, Combretum. glutinosum et Combretum. micranthum. Ainsi, les espèces Guiera senegalensis, Combretum glutinosum et Combretum micranthum peuvent être utilisées dans le reboisement de sites aménagés avec des banquettes sylvopastorales pour restaurer les terres de plateaux au Niger Silvopastoral banquettes are one of the techniques mostly used in Niger to restore degraded plateau lands. The present experiment was carried out on a degraded Simiri plateau in western Niger where silvopastoral banquettes have been installed. The objective is to assess the survival and growth of plants of four local species of Combretaceae, Combretum glutinosum, Combretum micranthum, Combretum nigricans, and Guiera senegalensis. The methods used consisted first of delimiting a space on the degraded plateau where 40 banquettes are made and another space without a banquette to serve as a control zone. In the banquettes, 200 plants of each species were planted at 20 plants/banquette. Two months after planting, periodic monitoring of soil moisture and dendrometric parameters of the plants was carried out for 30 months. The dendrometric parameters measured are the survival rate, the height and the collar diameter of the stem axis, the number of suckers and leaves. The results obtained showed on the one hand that the banquettes improve the water conditions of the soil by 18.19% compared to the untreated zone (without banquettes) and on the other hand that the best survival and growth rates were observed at the level of the species Guiera senegalensis, Combretum. glutinosum and Combretum. micranthum. Thus, Guiera senegalensis, Combretum glutinosum, and Combretum micranthum species can be used in the reforestation of sites developed with silvopastoral banquettes to restore plateau lands in Niger.

Influence of urea fertilizer on early growth of African Rose Wood (Pterocarpus erinaceous Poir.) seedlings in Kaduna State, Northern Nigeria

Influence of urea fertilizer on early growth and development of Pterocarpus erinaceous seedlings were investigated. Two hundred (200) uniformly growing seedlings were transplanted into polythene pots filled with top soil. Four urea fertilizer rates (0.035; 0.065; 0.095; 0.0125 g) and control were applied to the seedlings in the pots 20 × 25 × 25 cm, filled with 800 g of top soil collected from forest plantation. Assessment on the metrical character of the seedlings was done fortnightly. The fertilization of the selected seedlings with urea fertilizer was done round the seedlings in the nursery pots using ring method. The experiment was laid out in a completely randomized design. The data were subjected to analysis of variance, and means were separated using Duncan’s multiple range test at p < 0.05. The results show that fertilizer rates had significant (p < 0.05) effect on the growth and development of seedlings of P. erinaceous. Seedlings treated with 0.095 g of urea produced the highest mean values of 12.00 ± 0.66 cm; 0.33 ± 0.01 mm; 190 cm2 and 12.65 ± 0.67 for stem height, collar diameter, leaf area (LA) and number of leaves respectively. Seedlings fed with 0.125 g had the lowest values of 11.19 ± 0.61cm for height, 0.32± 0.01 mm for collar diameter 11.54 ± 0.70 for number of leaves and 124 cm2 for the LA. Urea fertilizers had significant effect on the early growth of the seedlings, therefore fertilization at 0.095 g per pot is recommended for raising P. erinaceous seedlings.

iTRAQ-based quantitative proteome analysis insights into cold stress of Winter Rapeseed (Brassica rapa L.) grown in the field

Winter rapeseed (Brassica rapa L.) is a major oilseed crop in Northern China, where its production was severely affected by chilling and freezing stress. However, not much is known about the role of differentially accumulated proteins (DAPs) during the chilling and freezing stress. In this study, isobaric tag for relative and absolute quantification (iTRAQ) technology was performed to identify DAPs under freezing stress. To explore the molecular mechanisms of cold stress tolerance at the cellular and protein levels, the morphological and physiological differences in the shoot apical meristem (SAM) of two winter rapeseed varieties, Longyou 7 (cold-tolerant) and Lenox (cold-sensitive), were explored in field-grown plants. Compared to Lenox, Longyou 7 had a lower SAM height and higher collar diameter. The level of malondialdehyde (MDA) and indole-3-acetic acid (IAA) content was also decreased. Simultaneously, the soluble sugars (SS) content, superoxide dismutase (SOD) activity, peroxidase (POD) activity, soluble protein (SP) content, and collar diameter were increased in Longyou 7 as compared to Lenox. A total of 6330 proteins were identified. Among this, 98, 107, 183 and 111 DAPs were expressed in L7 CK/Le CK, L7 d/Le d, Le d/Le CK and L7 d/L7 CK, respectively. Quantitative real-time PCR (RT-qPCR) analysis of the coding genes for seventeen randomly selected DAPs was performed for validation. These DAPs were identified based on gene ontology enrichment analysis, which revealed that glutathione transferase activity, carbohydrate-binding, glutathione binding, metabolic process, and IAA response were closely associated with the cold stress response. In addition, some cold-induced proteins, such as glutathione S-transferase phi 2(GSTF2), might play an essential role during cold acclimation in the SAM of Brassica rapa. The present study provides valuable information on the involvement of DAPs during cold stress responses in Brassica rapa L, and hence could be used for breeding experiments.

Growth and Nitrogen Retranslocation of Nutrient-Loaded Clonal Betula alnoides Transplanted with or without Fertilization

Nutrient loading can improve the growth and nutrient content of nursery-grown Betula alnoides Buch.-Ham. ex D. Don, but it is unknown whether nutrient loading enhances growth and nutrient uptake after transplanting. Plants were grown with three nutrient loading treatments (N100, N200, and N400; 100, 200, and 400 mg N per plant as 15N-urea) in nursery containers and then transplanted into plastic pots, with or without controlled-release fertilizer (F0 and F10, 0 and 10 g per plant). The N400 plants had a smaller size but higher nitrogen concentration relative to the N100 and N200 plants before transplanting. However, 180 days after transplanting, the N200 and N400 plants had superior root collar diameter, root length, and root area compared to the N100 plants, due to an increase in 15N retranslocation to new stems and new leaves. Moreover, transplant fertilization (F10) enhanced the height, root collar diameter, root length, and plant dry mass, but not nitrogen concentration or retranslocation, relative to F0. We recommend that medium- and high-dose nutrient loading is implemented in B. alnoides nurseries to optimize growth after transplanting. Additional fertilizer at transplanting may be advantageous in supporting growth, owing to the rapid depletion of nutrient reserves after planting out in the field.

Growth Dynamics and Tree Shape of Common Beech ( Fagus sylvatica L.) in the International Provenance Test

Provenance tests of forest tree species are important experiments in silviculture and tree breeding. Their results provide information about provenances' growth, adaptability, and other features. The research aimed to determine the dynamics of growth and tree shape of common beech plants per provenances in the international provenance test in Bosnia and Herzegovina to choose the best provenances considering wood production and quality. Research was conducted in the provenance test containing eight provenances from Bosnia and Herzegovina, four from Germany, three from Serbia, two each from Croatia, Romania, and Switzerland, and one from Hungary. Provenance test was established in 2007 by planting 2-year-old and 3-year old seedlings. Height and root collar diameter were measured, and tree shape was assessed in 2019. Data were processed in SPSS 26.0. Descriptive statistics, variance analysis, multiple Duncan's test for all traits, and Pearson's coefficient of corelation among morphological traits and tree shape were calculated. Variance for the height and root collar diameter showed statistically significant differences among different ages of plants and among provenances. Provenance from Croatia (Dilj Čaglinski) had the highest, and provenance from Romania (Alba-Iulia) had the lowest average height. The highest average value of root collar diameter had provenance Dilj Čaglinski, and the lowest value had provenance Sihlwald (Switzerland). The highest percentage of category 10 (ideal tree form) had provenance Bad Wildbad (Germany), and categories 1-4 (no silviculture value) had provenance Alba-Iulia (Romania). Pearson's coefficient showed that height, root collar diameter, and tree shape are highly correlated. Considering all the above, when planning forest-breeding works, it is recommended to continue the research and favor provenances with the best growth and tree shape.

Land use impacts on Boswellia dalzielii Hutch. an African frankincense tree in Burkina Faso

Boswellia dalzielii Hutch., an African frankincense tree, is a socio-economically important aromatic and medicinal tree. It is currently threatened by uncontrolled exploitation, and therefore requires action to ensure its sustainable management. This study assessed the population structure and regeneration of its natural stands across three land use types in Burkina Faso: woodlands, fallows and farmlands. Sixty, fifty and fifty 50 m × 20 m plots were established respectively in woodlands, fallows and farmlands. All the plots were surveyed for adult tree (dbh ≥ 5 cm) density, dbh, total height and health conditions. Data on regeneration density (dbh < 5 cm), source (generative, stem shoots, suckers), total height and collar diameter were also collected. The results show similar total tree heights (7.0 m-9.0 m) but significantly (p < 0.05) smaller tree dbh in woodlands (mean ± SD: 20.5 ± 0.49 cm) and fallows (29.3 ± 0.64 cm) than in farmlands (32.8 ± 0.15 cm). Adult tree density (trees/ha) was 1.3 and 2.7 times higher in woodlands (82.37 ± 6.57) than in fallows (62.00 ± 3.98) and farmlands (30.02 ± 1.63), respectively. The density of regeneration in woodlands was 28 and 6 times higher than in fallows and farmlands, respectively. The majority (> 50%) of regenerating plants were suckers and no seedling regeneration was found in farmlands. The distribution of trees in diameter classes was J-shaped in woodlands, bell-shaped in farmlands and positive asymmetric in fallows, indicating recruitment bottlenecks. We found that 80.18% of individuals encountered were unhealthy. Intensive debarking and cutting were the main threats to the species and no conservation strategy was in place in the study region. We suggest measures to reduce intensive debarking and cutting, which should contribute to better management of the species.

Azospirillum brasilense INOCULATION ON SEED GERMINATION AND INITIAL GROWTH OF SEEDLINGS OF NATIVE FOREST SPECIES

Inoculation of rhizobacteria in seeds and plants has been documented as a stimulant and promoter of germination and growth of agricultural crops, but there is little information on native forest species. Therefore, the present study aims to evaluate the potential of Azospirillum brasilense inoculation in the germination of seeds and initial growth of seedlings of native forest species. The following experiments were carried out: (I) germination of seeds in germination chamber, and (II) initial growth of seedlings in nursery, both with four forest species (Cassia leptophylla, Lafoensia pacari, Mimosa flocculosa and Schinus terebinthifolius). For the four species, in both experiments, two treatments were used: inoculation of seeds with concentrated solution of A. brasilense and no inoculation of seeds (control). Physiological aspects of seed germination and seedling vigor were evaluated in the first experiment (germination speed, and length and dry weight of seedlings), and seedling growth was evaluated in the second experiment (height, collar diameter and dry weight of seedlings). Inoculation of A. brasilense in seeds of C. leptophylla, L. pacari, M. flocculosa and S. terebinthifolius did not promote beneficial or promising results for seed germination and initial growth of seedlings, so its use to produce seedlings of these species is not recommended.

Growth and physiological potential of Terminalia arjuna under elevated CO2 levels in Open top chamber condition

Terminalia arjuna is native to India and occurs naturally along the banks of streams and rivers. The species is characterized to dry deciduous forests. The present study was carried out for the growth and physiological changes of T. arjuna in different elevated CO2 levels. Open top chambers were used to expose plants to ambient and elevated CO2 concentrations (400 and 800 ppm). The experiment was conducted in the month of March to August in 2019 for six months. The results showed that the growth parameters, i.e. plant height, collar diameter, the number of leaves, were found to be increased in elevated CO2 conditions. The percentage increase in physiological parameters like photosynthetic rate (28.82), mesophyll efficiency (60 % more in elevated CO2 condition), CO2 concentration (55 % more in elevated CO2), vapour pressure deficit (4.83 at 800 ppm) and water use efficiency (5.94 at ppm) increased. In contrast, transpiration rate (5.38 at 800 ppm and 10.11 ppm at ambient condition) and stomatal conductance (30% less in 800 ppm) decreased under elevated CO2 compared to ambient conditions. The study concluded that changing climatic conditions and significantly elevated CO2 in future may profoundly influence plant growth and the physiological response of T. arjuna.