Plants

In the course of this study, a protocol for in vitro deposition of a rare plant for the Rostov region, Thymus calcareus, was developed. Before sterilization, the seeds must be subjected to weekly extreme stratification (-18{degrees}C). An effective method for sterilizing primary explants is a mixture of 96% ethanol and 3% hydrogen peroxide in a 1:1 ratio with an exposure time of 7 minutes, followed by three rinses with distilled water. The effective environment for seed initiation is 1/2 MS. The optimal nutrient medium for clonal reproduction of T.calcareus has been determined: 1/2 QL. During long-term cultivation of T.calcareus on a nutrient medium of 1/2 QL, 100% rhizogenesis of plants was observed. The effect of nutrient media, growth regulators and their concentrations on the multiplication and rhizogenesis of T.calcareus explants in vitro has been studied: for multiplication, it is most effective to use a 1/2 QL nutrient medium with the addition of low concentrations of KIN; for rhizogenesis, it is recommended to use QL nutrient media with low concentrations of IAA. The degree of change in the influence of environmental factors, growth regulators and their concentration on T.calcareus in vitro and their change over time on the multiplication rates were determined: the nutrient medium (Ffact = 4.72), the type of growth regulator (Ffact = 7.82) and its concentration (Ffact = 4.71) have a significant effect on the multiplication coefficient of explants. The effect of the factors remains almost unchanged for the mineral base and growth regulator, while the concentration of the growth stimulant increases significantly.; A significant effect on the shoot elongation index was found in the growth regulator (Ffact = 10.39) and its concentration (Ffact = 5.51), the influence of both factors increases

Leguminosae is the third most abundant family of angiosperm in the world, and have a distinct difference that serves to identify and differentiate closely related species. Among 650 genera and 18,000 species of legumes in India, Tephrosia is the most emerged genus, of which two endangered and narrow endemic species Tephrosia jamnagarensis Sant and T. colina var. lanuginocarpa Sharma, possess a greater challenges for biological, ecological, and competitive improvement than other plants. Both the species are very unique and only found in a few isolated pockets of Gujarat around the globe. Therefore, in light of this, the present research aims to understand how morphological, anatomical, and genetically both species vary based on their variability nature are contextualized in an Indian context. Studies carried out on Morpho-anatomical observations and classical taxonomic approaches, such as the axillary cyme vs terminal raceme in T. jamnagarensis vs T. colina var. lanuginocarpa Sharma, the corolla being 4.5 cm long vs 1.5 cm long, the wings being 5.5 cm long vs 1.40 cm long, the keel being 3.4 cm long vs 1.5 cm long. First, ever genetic identity of the plants was assessed by using matK gene of the rbcl chloroplast region, and phylogenetic trees were constructed using sister clade separation. Sequences of both the plant species and others species that are found in India were submitted to NCBI and the embryonic stage of seeds were then used to examine seed morphology and propagation.

As part of the work, the key factors influencing the growth and development of Artemisia salsoloides culture have been studied, and nutrient media have been developed and optimized for plant conservation. The optimal medium for the cultivation of A. salsoloides is MS + 2 mg/L MT. Viable suspensions were obtained. The MS nutrient medium and the BM1k nutrient medium developed by us are suitable for wormwood callusogenesis. The growth curves of cell suspensions have a standard S-shaped curve. In the A. salsoloides plants we studied, key genes for the synthesis of artemisinin-like compounds (ADS, CYP71AV1, DBR2) were found, except for the CPR gene.

Neem is a tropical tree that can adapt to a wide range of places and particularly to semi-arid conditions. As at present, it is grown in many Asian countries and also in the tropical regions of the western hemisphere. Genetic variability and diversity are a major requirement needed for both immediate results and the one ones thereafter adaptation of plant types in their original domain. The evaluation of genetic diversity of any species is extremely crucial for their sustainability, continuity, survival and gene manipulation. Major breakthroughs in the field of molecular biology was able to develop several tools for the investigation of genetic diversity at the genome level to determine phylogenetic relationships among inter or intra-species. The advent of molecular markers for the detection and exploitation of DNA polymorphism is one of the major breakthroughs in the world of molecular genetics. The importance of genetic diversity in plant germplasm conservation, especially in economically important species such as Azadirachtaindica, is enormous, particularly in Nigeria. The question is whether A. indica from different Agro-ecological zones have genetic variations or similarities. This was the bane of the current study, which used RAPD to look atgenetic diversity of 27 randomly selected neem trees within the agro-ecological zones in Northern Nigeria. A total of 9 primers were employed out of which only 5 were responsive (OPA-02, OPA-03, OPA-15 and OPA-19). These primers showed dissimilarities in the visible DNA bands among the various tree samples. There was evidence of genetic dissimilarities among the trees sampled. Differences in percentage polymorphism was reported, where it was reportedly highest among the Borno State tree samples (97.44%), compared to those in Yobe State with no polymorphism.

Albino Artocarpus heterophyllus Seedlings (AAS) were found in the preliminary investigation by our group and were used as materials for researching. The phenotype of AAS leaves were observed and measured. In parallel, the photosynthetic physiological parameters were determined under different photosynthetically active radiations (PAR). The results suggested that the length, width, area and thickness of AAS leaves were less than normal seedings. Likewise, the net photosynthetic rate, intercellular CO2 concentration, stomatal conductance and transpiration rate of AAS leaves were not susceptible to PAR in contrast to normal individuals. Furthermore, the transcriptome sequencing technology was performed to clarify the expression of genes related to photosynthesis. It is as expected that numerous down-regulated genes were found in the synthesis of photosynthetic pigments, as well as the pathways of photosynthesis - antenna proteins, photoreaction and carbon fixation reaction of AAS leaves. Compared to other albino plants, AAS have a longer life span and more stable phenotypic traits with larger leaves, which could provide ideal materials for investigating photosynthesis of woody plants.

The African Sandalwood plant (Osyris lanceolata) is a threatened shrub or a small hemi-parasitic tree endemic to East Africa and South African regions, which is being severely affected by fungus, uproot-ing for oil extraction, poor natural regeneration, phenological structures (dioecious), medicinal values, lack of sexual recruitment, habitat loss, anthropogenic and climate factors and life span of its seed is short. It has been found a chllange through application of in situ conservation of natural trees like osyris lanceoleta since rapid human population growth and dramatically change the demands of fuel wood and agriculture investement, the available natural strands of valuable plants of African sandalwood have not been able to meet the demands of the people in world specifically developing countries. How ever, this study via using the advances of plant propagation method it provide new options for conserving and multiplication of Osyris lanceolata species using in vitro culture techniques of using IBA hormone by taking plant material of the targated plant. Propagation of African sandalwood (Osyris lanceolata) by rooting hormone of IBA in non-mist poly-propagator was investigated by taking young stem of osyris lanceoleta from Bazawit Hill and we provide an alternative propagation technique to the use of seeds. This Hill is near to Bahrdar town, Ethiopia.New leaf were initiated on the young stems of the osyris after six weeks of the experment.The influence of IBA as rooting promoter at three concentrations (50, 100 and 150 ppm) were recorded.Un expectedly, from the data collected it was observed that the success 83.3% can be achieved from young stem of un treatead cuting gave a new leaf and 50% were achived in the treatead plant, this propagation technique is a viable alternative to seed. The success may influenced by application orgin of a stem cutting with a type of soil.

Tanacetum vulgare L., known as tansy, is a perennial plant with a highly variable terpenoid composition, with mono- and sesquiterpenoids being the most abundant. The high diversity of terpenoids is known to play an important role in mediating ecological interactions. However, the distribution of terpenoids in different tissues and the inducibility of terpenoids in these tissues by biotic stress are poorly understood. In this study, we investigated the changes in terpenoid profiles and concentrations in different plant organs following treatment of roots with pipecolic acid (Pip). Pipecolic acid is a non-proteinogenic amino acid that triggers defense responses in plants. It is often used to induce systemic resistance (SAR) in plants under controlled conditions. Examination of the tissues showed that the leaves and midribs contained mainly monoterpenoids, while the coarse and fine roots of the plants contained mainly sesquiterpenoids. The rhizomes occupied an intermediate position by presenting the terpenoid profiles of both the midribs and roots but also the unique compounds of its own. Treatment with pipecolic acid led to an increase in the concentration of mono- and sesquiterpenoids in all tissues except rhizomes. However, a significantly higher amount of sesquiterpenoids was formed in root tissues in response to Pip compared to shoots. The metabolic atlas for terpenoids presented here shows that there is an exceptionally strong differentiation of terpenoid patterns and terpenoid contents in the different tissues of tansy. This, together with the differential inducibility by biotic stress, suggests that the chemical diversity of terpenoids may play an important role in the ecological interactions of tansy and in the defense against biotic stressors that feed on the below- and above-ground organs of the plant.

Saxicolella Engl., an African genus of the waterfall specialist plant family Podostemaceae, was shown to be polyphyletic as currently delimited. One clade, sampled from species in Ghana, is sister to American Ceratolacis (Tul.)Wedd., Podostemum Michx. and all Old World Podostemoideae (podostemoids). The second clade, sampled from Cameroonian material, was embedded within the major clade of African podostemoids. In this paper the generic nomenclature applied to Saxicolella sensu lato (Saxicolella, Pohliella Engl., Aulea Lebrun & Stork nom. inval.), is reviewed and the morphological support for the two clades and their correct generic names is determined. Pohliella is shown to be the correct name for the first clade (based on Pohliella laciniata Engl., Cameroon) and a synoptic treatment of its three published species is given, one of which is extinct, and two are threatened. However, a fourth, unpublished species exists. The new combinations Pohliella submersa (J.B.Hall) Cheek and Pohliella amicorum (J.B. Hall) Cheek are made for the two published Ghanaian species. The recently described New World genus Cipoia C.T. Philbrick, Novelo & Irgang is revealed as being morphologically identical to Pohliella, but in view of the geographical disjunction, confirmation from molecular evidence is awaited before its two species are also transferred to Pohliella. The correct name for the second clade, embedded in African podostemoids, is Saxicolella (sensu stricto), now with two known species, Saxicolella nana Engl. (type of Saxicolella, Cameroon) and Saxicolella flabellata (G.Taylor) C. Cusset (Nigeria).

A comprehensive microscopic investigation of the leaf epidermis, as well as anatomical and palynological research of selected Asteraceae species from the flora of Havali (Kahutta) Azad Jammu and Kashmir (AJK) Pakistan, was carried out. This study includes 11 plant species comprising of Senecio jacobea, Leucanthemum vulgare, Halianthus annuus, Erigeron bonariensis, Achillea millifolium, Halianthus Linnaeus, Taraxacum officinale, Anaphalius nepalensis, Erigeron Canadensis, and Tagetes erecta. All the species studied were amphistomatic, with four different forms of stomata i.e tetracytic, anomocytic, anisocytic, and tricytic. The main stomatal type was tetracytic, followed by anomocytic. The abaxial epidermis has a higher stomatal density than the adaxial epidermis. Highest stomatal density was present Tagetes erecta while lowest is present in Conyza canadensis. In lower epidermis stomatal index was higher in Taraxacum officinale followed by Halianthus annuus and Tagetes erecta while in upper epidermis highest index was shown by Halianthus annuus. For this study species of family Acteraceae were properly collected. Furthermore, variation in pollen can be seen. List of palynomorph which includes family name, botanical name, local name, English name, flower colour, season and pollen description for the logical arrangement of these species. The logical ordering of these species was guided by dust characteristics such as form and pollen morphology. Palynological data has been found to be too big for taxonomists to calculate and make appropriate observations on their findings.

Interspecific hybrids development by traditional breeding is challenging because of the incompatibility between two cultivated species of genus Corchorus. Under this condition, plant genetic transformation is an alternative tool for the improvement of jute cultivar. In the present study, in vitro multiple shoot regeneration protocol has been developed in jute (Corchorus capsularis cv. JRC 321) from excised embryonic axis as an explant by removing cotyledons, radicle, and tip of epicotyl. The explant is cultured in medium SMM1 supplemented with BAP (1.0 mg/L) for one week and sub-cultured in SMM6 containing IBA (0.5 mg/L) and BAP (0.2 mg/L). Direct adventitious shoot bud formation was observed from cotyledonary nodes and the adjacent region of excised embryonic axis. Interestingly, shoot bud formation was reduced when excised explants with intact epicotyl were cultured in the media combination (SMM1+SMM6) indicating the presence of apical dominance might be the cause of fewer shoot bud formation. While, hypocotyl explants did not produce any shoot in this media combination because nodal meristem was removed. However, the shoot buds developed from the excised embryonic axis were differentiated successfully into multiple shoots and showed further elongation in SMM6 which ultimately rooted in MS-B5 medium (+0.5 mg/L IBA). The plants were transferred successfully in the glasshouse conditions and appeared phenotypically normal.

The species-rich genus Inga (Leguminosae) presents ca. 300 species widespread throughout the Neotropics and is recognized by its recent and rapid diversification. Forty-eight species of Inga are endemic of the Brazilian Atlantic Forest. Among them, Inga subnuda, with two subspecies: subsp. subnuda, which occurs from the state of Paraiba to Rio de Janeiro; and subsp. luschnathiana, which occurs from Espirito Santo to the state of Santa Catarina. Both subspecies occur in sympatry in the southeastern region and share floral and leaf characters, which hampers the morphological delimitation. The co-occurrence of Inga vera subsp. affinis. with both I. subnuda subspecies results in intermediate morphologies between I. vera subsp. affinis and I. subnuda subsp. luschnathiana, making the distinction between the latter species even harder. We sampled 94 individuals from 8 natural populations and evaluated morphological characters previously described as distinctive among the subspecies of I. subnuda in addition to others not measured yet. We used 84 plastid (trnD-trnT spacer) and 58 nuclear (ITS 1 and 2) sequences to characterize the phylogenetic relationships between the taxa. The results obtained point out I. subnuda subsp. subnuda as a more structured taxon in relation to the other subspecies, whilst I. subnuda subsp. luschnathiana and I. vera subsp. affinis constituted a cohesive group. The apportionment of haplotypes differed between the markers used, thus evincing a retention of ancestral polymorphism between the subspecies, given their recent diversification. This paper explores different lines of evidence, thus contributing to the delimitation of these species. Demographic and biogeographic scenarios are also discussed. A new status of for the taxon currently circumscribed as Inga subnuda subsp. luschnathiana is suggested.

Invasive species serve as natural experiments to study adaptive evolution over contemporary time scales, as their native and invasive populations are exposed to different climatic settings and hence may experience strong selection pressures. In the life cycle of plants, germination stands as a cornerstone; thus, when invasive plant species encounter new surroundings, it is primarily expected that their germination niche will adapt to align with the thermal characteristics of the environment. However, adaptive responses in germination traits, specifically in cardinal temperatures, have not been explored. The objective of this study is to compare the Amaranthus albus (tumble pigweed) germination thermal niche and ecological niche between its native and invaded ranges. Considering geographic areas and climatic conditions, populations of A. albus were gathered from both cold and warm habitats in its native range (US) and its invaded range (Israel), with populations being at least 20 km apart from each other. First, populations were grown under similar conditions in a common garden experiment until seed production. The progeny seeds produced were then subjected to a set of germination trials under gradually changing temperature regimes. Cardinal temperatures and thermal niches for each population were estimated and analyzed in relation to the local climatic conditions of their respective habitats. Finally, a germination window was calculated to characterize the germination of a population throughout the year within its habitat. The invaded range studied here represents a subset of the species native range, with the A. albus establishing in similar climatic surroundings. Similarly, the germination niche for the native range was wider than for the invaded range. Thermal differentiation is evident in both native and invaded ranges. Populations from colder habitats exhibit lower base temperatures than those from warmer ones. This association was more evident for native populations. The remarkable variability observed within the germination pattern completely disappeared in the germination window produced by those models, resulting in a similar pattern across the year for all populations. Our findings demonstrate the capability of species to adapt to new environmental conditions that may arise due to climatic changes. It emphasizes the role of cardinal temperatures, specifically the base temperature, as a potential adaptive characteristic.

Three new species of Polycarpaea from Vietnam, P. vanana, P. chungana, P. duongana are described and illustrated based on evidence of molecular sequence data from two markers (ITS1-5.8S-ITS2 and rps16) and combined morphological characteristics. Polycarpaea vanana is closely related to Polycarpaea gaudichaudi, P. arenaria, P. duongana but differs by its stem glabrous, leaf ovate to elliptic, glabrous, ovary oblong ovoid, base obtuse, apex attenuate, capsule oblong void, 3.8 mm long. P. duongana differs from the three species mentioned above by its stem being densely villous, leaf spathulate, ciliate, ovary ovoid, base acute, apex obtuse, capsule ovoid, 1.2 mm long. Polycarpaea chungana is most similar to P. lignosa but differs in having leaf oblong or linear, sparse ciliate, sepal and petal apex deeply concaved or slightly bifid, ovary ovoid, ovoid, 0.8-1.0 mm long. Furthermore, the achievements of analysis using molecular data on the systematic positions of 7 other species are results that have not been in previous molecular analyses.

DNA barcodes have been considered as a tool to facilitate species identification based on their simplicity and high-level accuracy compression to the complexity and subjective biases linked to morphological identification of taxa. MaturaseK gene "MatK" of the chloroplast is very crucial in the plant system which is involved in the group II intron splicing. The main objective of this current study is determining the relative utility of the "MatK" chloroplast gene for barcoding in fifteen legume trees by both single region and multiregional approaches. The chloroplast "MatK" gene sequences were submitted to GenBank and accession numbers (GenBank: LC602060, LC602154, LC602263, LC603347, LC603655, LC603845, LC603846, LC603847, LC604717, LC604718, LC605994, LC604799, LC605995, LC606468, LC606469) were obtained with sequence length ranging from 730 to 1545 nucleotides. These DNA sequences were aligned with database sequence using PROMALS server, Clustal Omega server and Bioedit program. Also, the maximum likelihood and neighbor-joining algorithms for phylogenetic reconstruction using the MEGA-X program were employed. Overall, these results indicated that the phylogenetic tree analysis and the evolutionary distances of an individual dataset of each species were agreed with a phylogenetic tree of all each other consisting of two clades, the first clade comprising (Enterolobium contortisiliquum, Albizia lebbek), Acacia saligna, Leucaena leucocephala, Dichrostachys Cinerea, (Delonix regia, Parkinsonia aculeata), (Senna surattensis, Cassia fistula, Cassia javanica) and Schotia brachypetala were more closely to each other, respectively. The remaining four species of Erythrina humeana, (Sophora secundiflora, Dalbergia Sissoo, Tipuana Tipu) constituted the second clade. Therefore, MatK gene is considered promising a candidate for DNA barcoding in plant family Fabaceae and providing a clear relationship between the families. Moreover, their sequences could be successfully utilized in single nucleotide polymorphism (SNP) or part of the sequence as DNA fragment analysis utilizing polymerase chain reaction (PCR) in plant systematic.

There are various plants that grow in high elevations and experience various environmental stresses, cold stress being the most prevalent one. Plants undergo biochemical, metabolic, molecular, and physiological changes under cold stress hence, they adopt various mechanisms to tolerate it. The antioxidant defense system, osmotic regulators and photosynthetic pigments in the plant provide them stress tolerance. The present study is conducted on a high-altitude plant, Picrorhiza kurroa which grows in such environmental conditions, to study the physiological parameters that provides it the coping mechanism against the cold stress. For this study, the leaves were collected from Pothivasa (2200 m asl) and Tungnath (3600 m asl) in Rudraprayag, Uttarakhand, India. The photosynthetic pigments, lipid peroxidation, antioxidant enzymes, and osmoprotectants present in the leaves were determined to visualize the impact of cold stress. It was revealed that the concentration of chlorophyll a, chlorophyll b, and carotenoids increased with increase in elevation. The activity of SOD, CAT, POD, APOX and GR were analyzed and they were observed to decrease with altitude. The MDA concentration which is an indicator of lipid peroxidation is higher in Pothivasa (2.214 mol L-1) and lower in Tungnath (1.697 mol L-1). There is a significant increase in the total protein content, total soluble sugar content and total proline content along the altitudinal gradient. Therefore, the leaves from both the sampling locations revealed the physiological changes occurred in them to adapt to the cold stress conditions.

The Fusarium oxysporum species complex (FOSC) contains highly specific plant pathogens and some nonpathogenic strains, such as Fo47. In our work we concentrated on Fusarium oxysporum f.sp. lini (Foln), the specific flax pathogen and the endophytic strain Fusarium oxysporum 47 (Fo47), which is possibly protective for flax against pathogens. We investigated the influence of apocarotenoids like ionones and abscisic acid (ABA) on growth and development of these fungal strains considering possible fungicidal abilities of mentioned substances and comparing responses of fungi. The study shows inhibitory effect of ionones on mycelium growth of both Foln and Fo47. Our results also show the differences in apocarotenoids effect on studied strains in regards of sporulation, FUB genes cluster activity and fusaric acid (FA) production. Author summaryIn this study, we investigated the interaction between Fusarium oxysporum, a fungus that can either harm or potentially benefit plants, and natural plant-derived compounds known as apocarotenoids. We focused on two fungal strains: one that specifically infects flax plants, causing disease, and a nonpathogenic strain that may protect flax from pathogens. By examining the effects of apocarotenoids like ionones and abscisic acid, we aimed to understand how these compounds influence fungal growth, sporulation, toxin production, and gene activity related to pathogenicity. Our findings reveal that ionones inhibit the growth of both strains, suggesting their potential as antifungal agents. Interestingly, the two strains showed distinct responses to these compounds, particularly in their production of fusaric acid and activation of toxin-related genes. These results highlight the complexity of fungal interactions with plant-derived molecules and suggest that apocarotenoids could play a role in modulating fungal behavior. This work contributes to our understanding of plant-fungal interactions and may inform future strategies for managing crop diseases sustainably.

Pellaea ovata is a widespread species, sexual diploid in Texas &northeastern Mexico but an apogamous triploid in northwestern Mexico, south to northern Argentina, &on Hispaniola. The type belongs to the southern, apogamous triploid form. Although these two forms have been discussed repeatedly in the literature, morphological distinctions between them have been overlooked and they have not been recognized taxonomically. However, they are distinct. Pellaea ovata s.s. has puberulent rachides & costae; pinnae usually 2-pinnate with a well-defined main axis &pinnules borne singly; fertile pinnules ovate, cordate basally &rounded apically. The sexual diploid form has rachides &costae glabrous; pinnae pseudo-dichotomously branched &pinnules usually paired; fertile pinnules narrowly rounded-trapeziform, obliquely truncate to cordate basally &truncate apically. Riddell named the sexual diploid form Pteris zygophylla, from which I give it the new combination Pellaea zygophylla.

We report the complete chloroplast sequences of two varieties of Theobroma cacao collected in the Bolivian Amazonia using Next-Generation Sequencing. Comparisons made between these two chloroplast genomes and the Belizean reference plastid genome identified 19 and 22 nucleotide variants. The phylogenetic analysis reported three main T. cacao clades belonging to the Forastero, Criollo and Trinitario groups. The Bolivian Native Cacao varieties were located inside the Trinitario group forming their unique branch. The Bolivian Native Cacao branch reveals a possible new subpopulation different from the well-characterized T. cacao subpopulations. The phylogenetic trees showed that the relationships among the T. cacao varieties were consistent with their geographical locations placing the Cacao Center of Origin in Western Amazon. The data presented here will contribute to the usage of ultrabarcoding to distinguish different T. cacao varieties and to identify native cacaos from introduced cacaos. Thus helping in the conservation of local native varieties of T. cacao.

Keetia nodulosa Cheek, a cloud forest climber nearly endemic to Cameroon, with a single record from Nigeria, is described and illustrated. It is remarkable as the first known species to be recorded with bacterial leaf nodules (BLN) in the genus Keetia, and also, in the tribe Vanguerieae. Other genera in Rubiaceae with BLN are Psychotria (Psychotrieae), Sericanthe (Coffeaeae) and Pavetta (Pavetteae). The BLN in Keetia (Vanguerieae) are illustrated for the first time here. The characteristics and significance of bacterial leaf nodulation in Keetia nodulosa are discussed in the context of rapidly growing knowledge on the subject in flowering plants. Keetia nodulosa is provisionally assessed using the 2012 IUCN standard as Endangered (EN B2ab(iii). The importance of its conservation, and options for achieving this are discussed in the context of recent extinctions of other plant species in Cameroon. This discovery of a new cloud forest species is discussed in relation to other cloud forest plant species described in the last twenty years which are also distributed over the highlands of the western half of Cameroon.

Morphology of Dendrophthoe falcata (L. f.) Ettingsh var coccinea is described in detail from West Bengal with notes on the histology of haustorium. Structural peculiarity of the style is explained in the light of embryo sac development. Section of immature fruit shows different zones including embryo. Three types of haustoria namely woody gall, clasping union ad epicortical root is observed in different species of the host plant. Section of haustorium shows penetration peg which reach the host xylem to suck the sap. In guava plant, two types of haustoria develop - primary or true haustorium which penetrate the host stem and secondary haustorium which develop in between two roots of the parasite. Secondary haustorium is oval in shape with a few concentric rings like thickening and never develops penetration peg.