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In many cases over the years the diversity of Isoetes in India has been defined by inconsistent morphological analyses and questionable data. This has resulted in substantial confusion, dramaticall...

The article presents the results of a study of the ligule morphology of both vegetative and reproductive leaves of four species of Selaginella, i.e. S. delicatula, S. ganguliana, S. plana and S. tenera, occurring in India. Ligules of S. ganguliana, S. plana and S. tenera are described for the first time, and the occurrence of shuttlecock-like ligules is described for the first time. Ligule shape is generally constant across the species studied but some minor morphological variations are observed within species. However, in combination with other morphological characters, the ligule may be a useful tool in the taxonomic delimitation of closely related Selaginella species. In addition, we propose that ligule size may be influenced by the habitat conditions, whereas the presence of glandular cells at their tip margins possibly indicate a water secreting function.

Selaginella odishana (subg. Stachygynandrum) is described as a new terrestrial species (probably a local endemic) from the Sal tree (Shorea robusta) forest on hill slopes of Daringbadi, Daringbadi Udayagiri forest range, Kandhamal district, Odisha state, Eastern Ghats region of India, and compared to morphologically close taxa (S. reticulata and its allied taxa). The new species is characterised by sub-erect stems, membranous leaf, lateral and axillary leaf, ciliate at the base and serrate distally (towards stem tips) and only serrate (outside face) or serrate margin, lanceolate median leaf with entire-serrate margins, dorsal sporophyll with serrate margins and laminar flap up to ¾ as long as lamina length with ciliate margins, ventral sporophyll ciliate along basal ½ and serrate along distal ½, creamy white megaspores with foveolate surface ornamentation and microspores with smooth surface ornamentation. The conservation status of S. odishana is assessed as Critically Endangered.

The study presents the morpho-physiological performance under induced drought condition and molecular marker based genetic variability amongst 13 rice varieties released for cultivation in Uttar Pradesh, India. An attempt was made to identify suitable genotypes for drought affected areas, based on their morpho-physiological characteristics and genetic diversity. The physiological parameters of photosynthesis rate (A), transpiration rate (E), water use efficiency (WUE), along with the yield parameters and genetic diversity by simple sequence repeats marker (SSR) profile were analysed. The rice varieties PR-115 and PR-113 exhibited high water use efficiency, suggesting its possible advantageous response to drought due to low transpiration and high rate of net photosynthesis. The varieties, PR-115 and PR-113 were also found to be best performer in terms of yield under drought conditions. However, the more widely cultivated varieties namely Basmati, IR-36 and IR-20 were found to be intermediate in their response to drought for both yield and physiological parameters. The 19 simple sequence repeats marker (SSR) produces a total of 64 alleles across the 13 varieties, with alleles ranging from 2 to 7 per locus (average 3 alleles). The Polymorphic information content (PIC) value ranged from 0.13 to 0.78 with an average of 0.45 ± 0.19.

A new umbellate ornamentation pattern is described in Isoetes megaspores based on scanning electron microscopy and thorough comparisons with sculptural patterns documented in lycophytes and ferns. The umbellate ornamentation is quite distinct from other vertically projected megaspore sculptural patterns (baculate, clavate, gemmulate, pustulate, tuberculate, saccate and verrucate). In addition, megaspore ornamentations described previously for I. dixitei as tuberculate or pustulate have now been corrected as umbellate. This species also possesses a rudimentary velum and internal pigmentation in sporangial wall which has not been reported in other Indian species of the genus. Further, this taxa has a range restricted to the Western Ghats and is confined to a higher elevational range than Indian species characterised by vertically projected megaspore surface ornamentation patterns.

Twenty Indian species of the lycopod genus Selaginella are studied using both light microscopy and scanning electron microscopy to resolve the variability in the number of megaspores per megasporangium and size, surface ornamentation and micro-sculpture of the megaspores. Comparisons between the new results and previous findings suggest that spore morphology and size are consistent for some species but variable within others.

The present study provides a comparative morphological analysis of spikes in different Indian species of Selaginella. The salient features of spikes including their types and also the shape and margin of sporophylls of the closely related taxa are characteristically useful in taxonomic delineation. We have used the term Leaf-flap, for the first time, and the Sporophyll-pteryx to denote the occurrence of vertical/oblique projection on the dorsal surface of leaf and sporophyll, respectively. The shape and colour of both mega- and micro-sporangia are also helpful in taxonomy; however, their size is not much significant as these are variable within the same spike of the species. A new pattern of sporangial distribution is being reported for the first time in the spike of S. plana (Desv. ex Poir.) Hieron.

Two rice varieties PR-115 and Super-7 were imposed to water stress and different physiological traits were monitored to evaluate the performance of these varieties under drought. Under water stress condition although the relative water content, osmotic potential, chlorophyll content, photosynthesis rate, carbon discrimination and biomass decreased in both the varieties however, the reduction was more pronounced in Super-7 variety. Oryzanol a trans-ester of ferulic acid functions as antioxidant and it increased along with total phenolic and anthocyanin content in both the varieties under drought stress. However, gallic acid, 4 hydroxy benzoic acid, syringic acid and chlorogenic acid showed differential pattern in both of the varieties under water limiting conditions. Under drought, grain yield was penalized by 17 and 54% in PR-115 and Super-7 varieties, respectively in comparison to watered plants. Super-7 variety showed pronounced electrolyte leakage and MDA enhancement under water stress condition. High non photochemical quenching and reduction in Y(NO) and Y(II) indicated balanced energy management in tolerant PR-115 variety. The studies showed that PR-115 is a drought tolerant variety while Super-7 is drought sensitive in nature.

Isoetes ×gopalkrishnae hybr. nov., is described, illustrated and compared with possible parent species. Based on morphological characteristics and habitat conditions, this taxon is considered to represent a sterile hybrid between I. coromandelina and I. panchananii. The new hybrid is amphibious and grows on the exposed shore of an artificial pond. It is known only from a single locality on the Vindhya plateau in Uttar Pradesh, India. It can be distinguished from other taxa by a combination of characters including the lack of a scale, the leaf which is terete in transverse section, velum absent to rudimentary, a sporangial wall with internal pigmentation, rugulate megaspores with a smooth equatorial girdle and microspores with densely echinate to short-cristate ornamentation. It is the first Isoetes hybrid reported from the Indian subcontinent.

The oomycete, Phytophthora infestans, is one of the most important plant pathogens worldwide. Much of the pathogenic success of P. infestans, the potato late blight agent, relies on its ability to generate large amounts of sporangia from mycelia, which release zoospores that encyst and form infection structures. Until recently, little was known about the molecular basis of oomycete pathogenicity by the avirulence molecules that are perceived by host defenses. To understand the molecular mechanisms interplay in the pathogen and host interactions, knowledge of the genome structure was most important, which is available now after genome sequencing. The mechanism of biotrophic interaction between potato and P. infestans could be determined by understanding the effector biology of the pathogen, which is until now poorly understood. The recent availability of oomycete genome will help in understanding of the signal transduction pathways followed by apoplastic and cytoplasmic effectors for translocation into host cell. Finally based on genomics, novel strategies could be developed for effective management of the crop losses due to the late blight disease.

Nanotechnology has the potential to reinforce the missiontoward ever-green revolution by enhancing agricultural productivity with limited inputs. Zinc plays a vital role in growth hormone production, internode elongation and sexual reproduction by affecting production and shape of pollen and changes in the stigma. Keeping above facts under consideration an experiment was conducted to study the effect of Zincoxide nanoparticles(ZnONPs) on reproductive and biochemical parameters in sunflower. ZnONPs treated and untreated seeds of sunflower were grown in sand culture supplemented with zinc deficient Hoaglandsolution in order to provide representative indication of the impact of ZnONPs on plants under environmentally relevant conditions. Plants treated with ZnONPs exhibited early flowering, improved pollen viability and high starch content in pollens with respect tocontrol. Flowers bloomed first in seeds and plants treated with ZnONPs at a concentration of 250 ppm, followed by 1000 ppm oftreated seeds and untreated sand. The highest pollen viability was observed in treated seeds and treated plant at a concentrationof 500 ppm and the lowest in treated seeds with foliar application at 1000 ppm. Starch content was the highest at 250 ppm in treated seeds and untreated plants and the lowest in treated seeds and treated plants at 500 ppm concentration. This experiment revealed that ZnONPs has exhibited note worthy effect onreproductive and biochemical parameters of sunflower plant at different concentrations and under different modes of application.

The oomycete, Phytophthora infestans, is one of the most important plant pathogens worldwide. Much of the pathogenic success of P. infestans, the potato late blight agent, relies on its ability to generate large amounts of sporangia from mycelia, which release zoospores that encyst and form infection structures. Until recently, little was known about the molecular basis of oomycete pathogenicity by the avirulence molecules that are perceived by host defenses. To understand the molecular mechanisms interplay in the pathogen and host interactions, knowledge of the genome structure was most important, which is available now after genome sequencing. The mechanism of biotrophic interaction between potato and P. infestans could be determined by understanding the effector biology of the pathogen, which is until now poorly understood. The recent availability of oomycete genome will help in understanding of the signal transduction pathways followed by apoplastic and cytoplasmic effectors for translocation into host cell. Finally based on genomics, novel strategies could be developed for effective management of the crop losses due to the late blight disease.

Drought is a major stress that dramatically limits plant growth and productivity. Polyethylene glycol (PEG) has been used for osmotically induced water stress studies in plants. The present work was designed to examine the biochemical response in six barley varieties (three tolerant and three sensitive) at different osmotic potential of Polyethylene glycol-6000 (PEG-6000). The results showed at-3.0 bars osmotic potential of PEG-6000 decreased total chlorophyll and an increase in electrolyte leakage and catalase activity was observed in barley leaves.

Agriculture is the backbone of most developing countries and it provides food for humans, directly and indirectly. Agricultural practices are catching public attention globally because climate change, energy and resource constraints, and rapidly growing global population are constantly increasing pressure on food and water resources. The use of nanoparticles in crop sciences is consistently increasing. Several advantageous effects of nanoparticles have been observed on crop plants. Copper (Cu) is an essential nutrient for the growth of plants and plays an important role in the photosynthetic reactions. Copper activates several enzymes, contributes in RNA synthesis and improve the performance of photosystems. But at higher level of Cu, seed germination and plant growth may be adversely affected. In the present study we administered copper oxide nanoparticle in varying concentration to assess the changes in germination percentage, root and shoot length, vigor index and total chlorophyll in soybean. Results showed a significant change in all the above parameters at 200ppm concentration in response to control. Thereafter high concentration of copper oxide nanoparticle proved to be toxic resulting in decrease in plant germination and decrease in vigor index and total chlorophyll.

Mahabaleshwar in Maharashtra, India. They were determined by the authors as belonging to that species on the basis of descriptions and illustrations given by Shende (1945) since the type specimen was not available for comparison. Microspores were acetolysed with acetic anhydride and concentrated sulphuric acid according to the method of Erdtman (1952). Megaspores were studied after treating them with 30% HF for 24 hours to dissolve the perispore and untreated. LM microphotographs were taken in transmitted and refracted light using a Nikon HFX-IIA Optiphot and SEM microphotographs with a JEOL SEM 35C model after coating the dry spores with a thin conductive film of gold palladium about 200 A in thickness, in an ion sputter coater (JFC 1100). SEM studies of microspores and megaspores were conducted at the National Botanical Research Institute, Lucknow. The details of the SEM wall ultrastructure of the spores of I. dixitei are described in the text. The descriptive terms used in the present paper have been taken from the glossaries given by Jackson (1928), Kremp (1965) and Hickey (1966). The mircospores (Fig. 2, A-F) are bilateral-monolete or tetrahedral-trilete, 16-45(33) pm in diameter and their monolete and trilete proximal ridges are thin and high. The spore wall is three layered (described here as perispore, exospore and mesospore). The perispore is echinate. It appears granular under LM, but when scanned under SEM, its surface shows well defined sharply pointed and uniformly distributed "spines" whose broad bases may sometimes coalesce with one another to form intersecting muri. The exospore may be granular or it may show very fine and short muri. The mesospore forms a smooth walled round or oval sac which is firmly attached to the exospore. The megaspores (Fig. 1 A-R; Fig. 3 A-F, Fig. 4 A-H) are dimorphic i.e., of two different sizes: the larger megaspores are pyramidal globose, 440-610(515) pm in diameter. The smaller ones are flattened in the proximal distal plane and are 255-440(360) pm in diameter. As a rule the megaspores show tri-radiate ridges on the proximal side, but in rare specimens the ridges are tetra-radiate (Fig. 4, D). The proximal ridges are straight or sinuous and up to 70 pm high. The equatorial ridge is of variable height: at the junctions with the proximal ridges