Vietnam is one of the diverse regions for Araceae and possesses a large number of endemic Araceae species. Many Araceae species in Vietnam have been used as food and traditional medicines. Accordingly, species belonging to the genera, including Amorphohallus, Aglaonema, Arisaema, Alocasia, Colocasia, Homalomena, Lasia and Typhonium possessed many potential applications. Based on my knowledge and observations as well as the literatures on values of Araceae species, the present review aims to provide the information regarding the potential uses in medicine, food and ornamental plant industry of 27 Araceae species in Vietnam. In addition, the illustrative photos of all 27 Araceae species from this study are also given.
Genetic basis of heterosis has been exploited for yield improvement in safflower (Carthamus tinctorius L.) but little is known about physiological basis of heterosis for yield. The objective of this study was to quantify the physiological basis of heterosis for seed yield in safflower by examining 19 safflower hybrids and their parents for photosynthetic traits, and yield and its components. The results showed that heterosis for yield and its components was high and positive but was low and negative for photosynthetic traits in most of the hybrids studied. There were weak and non-significant relations between photosynthetic traits and yield and its components. Hybrids were more efficient in translocating photoassimilates to two major sink organs viz., number of seeds and number of capitula despite having low net photosynthesis than parents. Seed yield increase in safflower is more sink-than source-limited and was necessary through heterosis for sink organs. Heterosis breeding for larger sink size with parallel increase in effectiveness of sink organs in translocation of photo-assimilates is suggested for yield improvement in safflower.
Environmental adaptation and cell differentiation processes are factors that influence the anatomical elements of wood. The objective of this study was to investigate the effect of water deficit on lignin composition in anatomical elements and on the characteristics of vessel-neighboring cells. Six-year-old clones of Eucalyptus urophylla and Eucalyptus grandis × Eucalyptus camaldulensis from wet and dry regions were used. All regions received a rainfall exclusion treatment. Cell wall width, cell wall thickness, and form factor of fibers close to and far from vessels were measured. In the same cells, lignin was measured in the middle lamella and vessels by a fluorescence technique. The vessel differentiation process affected cell wall thickness and lignin composition in neighboring cells. Lignin composition was increased in vessels compared to fibers or vasicentric tracheids. Middle lamella lignin was not affected by vessel differentiation or water deficit in either eucalyptus clone. E. grandis × E. camaldulensis is originally from a dry climate region and, therefore, did not suffer alterations in lignin when subjected to water stress conditions; however, this clone exhibited a higher number of vasicentric tracheids. E. urophylla is originally from a humid climate region and, when subjected to water deficit, showed increased wood lignin composition, which seems to be a strategy for better use of water resources. Alterations in lignin composition of vessel, vasicentric tracheid, and fiber cell walls resulting from exposure to water deficit conditions vary according to eucalyptus species.
The present experiment was conducted to estimate the physico-chemical diversity of twelve Indian jujube cultivars. A sum of fifteen quantitative characters were explored and subjected to multivariate analyses. Significant variability was observed across the ber cultivars under study. Pearson’s correlation analysis identified days to first flower initiation, a higher number of flowers per cluster and a higher number of retained fruits per cluster which could be used as the basis of selection for identification of high yielding ber cultivars. The principal component analysis (PCA) estimates 60.2% of the total variability in ber cultivars is contributed by PC1 and PC2. The scatter plot of the first two components highlights the number of retained fruits per cluster, yield per tree, pulp weight, fruit width, stone weight and number of flowers per cluster as principal characters that played a significant role in the total variability. Further, PCA also helped to identify Mehrun, Manuki and Chhuhara as superior ber cultivars which performed well with respect to the PC1 and PC2. The Mahalanobis D2 statistics grouped all the twelve ber cultivars into five clusters indicating the existence of ample genetic diversity among the cultivars. Considering the inter-cluster distance along with cluster mean it could be concluded that the cultivars of cluster II and Cluster III may be utilized to estimate the combining ability for effective exploitation of heterosis or to isolate desirable transgressive segregants.
Jatropha curcas is an important biodiesel plant as its seed contains 27–40% oil. The virus infection causes adverse effects on plant growth, and yield. The present study was carried out to develop plantlets from virus-infected plants using meristematic cultures. Cultures were also raised using nodal explant to figure out culture loss caused by the new strain of Jatropha leaf curl Gujarat virus (JLCuGV). Poor (48.3 ± 15.1 %) shoot bud induction was noted in virus-infected explants on MS medium supplemented with 6-benzylaminopurine (BAP) and Indole-3-acetic acid (IAA). Severe culture loss was noted upon subsequent sub-cultures of nodal explants. Apical meristem (MC) developed the highest (86.3 ± 12.5 %) shoot bud induction on Murashige and Skoog (MS) medium supplemented with 0.5 mg/L Thidiazuron (TDZ). Best results in shoot proliferation and elongation were achieved on 1.0 mg/L BAP, 1.5 mg/L IAA and 0.5 mg/L Gibberellic acid (GA3) containing medium with 9.9 ± 1.7 number of shoot buds of 5.2 ± 0.5 cm shoot length. It was interesting to note that the rooting percentage was not affected by virus infection. Shoots obtained from virus-infected and meristem cultures rooted well without any significant difference in rooting percentage. It was known by the study that the generation of planting material from virus-infected plants was possible with meristem explants but recalcitrant with nodal explants.
Azolla is a small freshwater fern reproduces sexually and asexually (by splitting). The spores’ formation through sexual reproduction in the azolla species is influenced by climatic condition. Keeping this fact in view, the present study was conducted with an aim to study the impact of temperature on the sporocarp formation and also developing storage techniques for sexual propagation in the azolla species. The study showed that the sporulation in Azolla pinnata was more sensitive to increase in the temperature than Azolla microphylla. Azolla pinnata did not sporulate on rising maximum temperature; however sporulation in Azolla microphylla was delayed by one month due to rise in the temperature during second year compared to the first year. Conversion of the freshly collected sporocarps into Azolla microphylla plants were decreased by 4.2–9.3% on increasing minimum and maximum temperatures by 5°C and 8°C, respectively and conversion of the one month old sporocarps into plants was decreased by 1.8–8.7% on rising minimum and maximum temperatures. On storing sporocarps in the refrigerator resulted in higher germination percentage than stored at room temperature. Conversion of freshly collected sporocarps into Azolla plants increased on storage of the sporocarps mixing with soil (1:15) in the refrigerator than at room temperature. Germination of one month old Azolla microphylla sporocarps on storage in refrigerator after mixing with soil decreased during second year compared to first year. Therefore, in a controlled environment, azolla may be encouraged to grow sporocarps for exploiting full potential of azolla for eco-friendly agricultural and livestock management.
The use of plants that present clear physiological responses to heavy metals such as cadmium (Cd) can assist in environmental monitoring. The aim was to evaluate physiological responses of Cd in Alternanthera tenella plants in micro-controlled conditions and to assess the its tolerance level and bioindicator potential. Nodal segments of A. tenella were grown in flasks containing semi-solid MS medium supplemented with (0, 50, 100, and 150 μM Cd). The total fresh and dry weight of the plants, in addition to physiological analyses, were determined after 30 days of cultivation. Plants submitted to Cd showed a reduction in biomass and photosynthetic pigments content. The decline in the Chl a/b ratio indicated the deleterious effects of Cd, as evidenced by the decrease in the density of active reaction centers (RC/CSM). The levels of deterioration in the functionality or structural integrity of the thylakoid membranes (WL) and the activity of the oxygen evolution complex (WK) increased as a function of Cd concentrations. The decreases in photochemical and non-photochemical quenching (qP and qN, respectively) observed in plants exposed to Cd indicated photochemical dysfunctions. Additionally, the increase in the quantum yield of non-regulated energy dissipation (ΦNO) indicated the presence of photodamage. Plants had a low/intermediate TI level (≥21.7) in the analyzed concentration range. A. tenella plants can bioaccumulate high amounts of Cd. The level of physiological responses of A. tenella is dependent on the concentration of Cd, which makes the use of this species even more promising as a bioindicator for this metal.
This study highlights the importance of flower color variation and attraction as a mechanism for pollination and protection of floral parts. As part of this study, a survey relating to flower color variation and differences in spotting pattern (nectar guides) was conducted on Rhododendron arboreum, a widespread tree species in the mountainous region of Uttarakhand state, at 43 different altitudinal locations. Seven original color morphs of flowers and five types of spot variation in the nectar guide were observed. The study underlines the role of flower color polymorphism in both pollination and adaptation to varied environmental conditions. Further, the significance of nectar guides in directing the visitor to the reward is discussed. This study has the potential to enhance existing knowledge about flower color variation and attraction to the environment.
Lenticels can be defined as pores that are the entrance of a continuous aeration system from the atmosphere via the living bark to the secondary xylem in the otherwise protective layers of the periderm. Most work on lenticels has had an anatomical focus but the structure-function relationships of lenticels still remain poorly understood. Gas exchange has been considered the main function of lenticels, analogous to the stomata in leaves. In this perspective review, we introduce novel ideas pertaining to lenticel functions beyond gas exchange. We review studies on lenticel structure, as this knowledge can give information about structure-function relationships. The number of species investigated to-date is low and we provide suggestions for staining techniques for easy categorization of lenticel types. In the follow-up sections we review and bring together new hypotheses on lenticel functioning in the daily “normal operation range”, including regulative mechanisms for gas exchange and crack prevention, the “stress operation range” comprising flooding, drought and recovery from drought and the “emergency operation range”, which includes infestation by insects and pathogens, wounding and bending. We conclude that the significance of dermal tissues and particularly of lenticels for tree survival has so far been overlooked. This review aims to establish a new research discipline called “Phytodermatology”, which will help to fill knowledge gaps regarding tree survival by linking quantitative and qualitative lenticel anatomy to tree hydraulics and biomechanics. A first step into this direction will be to screen more species from a great diversity of biomes for their lenticel structure.
Groundnut is an important oilseed crops with high nutritional values. Yield of groundnut is constrained owing to diverse biotic and abiotic factors. Amongst biotic stresses two foremost foliar fungal diseases viz., late leaf spot and rust are universal and sparingly significant. Both conventional and modern breeding methods may be applied for improvement of groundnut. The current investigation was carried out to recognize genetic variability present among different groundnut germplasm with the use of morphological characters and SSR markers with the screening of resistant to leaf spot and rust resistant genotypes. In morphological examination, the analysis of variance divulged highly substantial differences among 48 germplasm lines. Initial screening of Germplasm was tried with the use of 125 SSR markers. But, based on banding pattern, 21 markers were found to be the best and selected for amplification of whole set of genotypes. Out of 21 markers, 16 were found to be highly polymorphic. Highest PIC value (0.8196) was detected for marker S021 representing 81% diversity. SSR Markers viz., PM42, PM204, PM377, S052, S076, S078 and S078 have PIC value more than 0.5, confirms their superiority in detection of polymorphism among studied germplasm lines. UPGMA analysis assemblage all the germplasm lines into three major clusters. Most of the foliar disease resistant genotypes were grouped together with higher genetic resemblance. Polymorphic markers identified in the study may be utilized further for molecular diversity analysis and the identified resistant genotypes may be employed further for the improvement of the crop.