Effect of placement of urea and coated urea fertilizers on yield and quality of soybean (Glycine max (L.) Merr.) seeds

The objective of the present study was to record the seed yield and to examine visually the quality of soybean seeds cultivated under different types and placements of urea fertilizers. In addition to the conventional fertilizer application (including ammonium sulfate 16 kg N ha^-1 broadcasting (100 kg N ha^-1 of urea (0B) and X00-d type coated urea CU-100 (CUB), and deep placement (100 kg N ha^-1) of urea (UD) and 100-d type coated urea CU-100 (CUD) was conducted in separate plots in a paddy field converted to an upland field located at Shindori Experimental Station of Niigata University. Soybean plant growth was periodically analyzed and the quality of harvested seeds was also visually examined (hereafter referred to as “visual quality”). It was found that the deep placement treatments were more conducive 1o nitrogen (N₂)fixation, based on the relative mreide N concentration in the xylem sap, which is a good indicator of N~fixation by soybean. Also the total seed yield was the highest in CUD (82 g plant^-1) and 0D (81 g plant^-1), compared to the control (62 g plant^-1), UB (68 g plant^-1), and CUB (68 g plant^-1). The visual quality of harvested seeds showed that CUD enhanced the quality of seeds compared to the other treatments, in which the percentage of good quality seeds, hereafter referred to as "good seeds," based on the dry weight was 51 (control), 65 (K3B), 61 (CUB), 61 (0D), and 6696 (CUD). In terms of diseased seeds, the percentage of turtle wrinkle and broken seed coats was found to decrease by N application compared to the control. Thus, it is suggested that N fertilization management is important for maximum yield of soybean as well as for the enhancement of seed quality.     

Planting stress, water status and non-structural carbohydrate concentrations in Corsican pine seedlings

Two-year-old Corsican pine (Pinus nigra ssp. laricio var. Corsicana) seedlings were either well watered or subjected to a moderate drought for one month before being lifted from the nursery bed on October 9 and transplanted. Well-watered, non-transplanted seedlings served as controls. Needle predawn water potential (Psi(wp)), non-structural carbohydrate concentrations and plant development (survival, bud break, shoot elongation) were assessed before and during the first growing season after transplanting. On April 16, just before bud break, Psi(wp) was lower for the well-watered + transplanted and drought-conditioned + transplanted seedlings (Psi(wp) = -1.45 and -1.83 MPa, respectively) than for the controls (Psi(wp) = -0.56). There was a close relationship between the Psi(wp) measured on April 16 and bud break, shoot elongation and plant survival during the following growing period. Above a Psi(wp) of -1.1 MPa, all plants developed normally. Between -1.1 MPa and -1.6 MPa, bud break, and thus shoot elongation, did not occur in all plants. Between -1.6 MPa and -2.1 MPa, the plants were characterized by the absence of shoot growth, but mortality was zero. Below -2.1 MPa, there was a large increase in plant mortality. On April 16, starch concentrations were markedly lower in the roots of transplanted seedlings than in the controls. There was a positive correlation between Psi(wp) and root starch concentration. The Psi(wp) (-2.3 MPa) at which complete starch depletion was observed in the roots corresponded to the Psi(wp) below which plants did not survive. These results suggest that mechanisms specifically linked to altered water status and metabolic processes associated with altered carbohydrate status are involved in transplanting stress; however, it was not possible to disentangle the two effects. Drought conditioning did not lead to a marked increase in soluble carbohydrate concentrations, as reported for other species, and did not increase plant tolerance to transplanting stress.     

Ploidy dependent expression of apomixis and its components in guinea grass (<Emphasis Type="Italic">Panicum maximum</Emphasis> Jacq.)

Panicum maximum (guinea grass) is a model crop for apomixis and polyploidy studies. It is predominantly tetraploid (2n?=?32) and is characterized by gametophytic apomixis, Panicum-type apospory and pseudogamous endosperm development. The three components of apomixis, viz. apomeiosis, parthenogenesis and functional endosperm development, can be uncoupled in this crop. An exhaustive single progenitor-derived ploidy series comprising of 32 accessions representing 3x, 4x, 5x, 6x, 7x, 8x, 9x and 11x cytotypes was utilized in present study to understand ploidy effects on expression of apospory as well on uncoupled components in two phases of progeny formation i.e. in matured ovules (using embryo-sac analysis) and in matured self-pollinated seeds (using Flow Cytometric Seed Screen method). Rise in ploidy enhanced the formation of sexual embryo-sacs (ES) thereby increasing the frequency of facultative accessions at higher ploidy level. Our results suggested that the eventual phenotype depends on relative doses of apospory and sexual factors in the genome. Ploidy level was also found affecting the penetrance and expressivity of uncoupled apomixis components. Formation of B_III hybrids (3n) appeared to be more stabilised and less affected by the ploidy change, however, formation of M₁ (1n) progenies increased with the rise in ploidy. Ploidy effects on traits such as occurrence of multiple ES, autonomous endosperm development, and twin embryos were also studied. Flexibility of guinea grass to tolerate excessive genome burden and successful formation of seeds overcoming endosperm balance number and endosperm imprinting constraints is also discussed.     

Assessment of the effectiveness of Ty genes in tomato against tomato leaf curl Bangalore virus

Tomato leaf curl Bangalore virus (ToLCBaV), a monopartite begomovirus transmitted by the whitefly Bemisia tabaci, has become a major constraint in tomato production in the Indian subcontinent. Earlier breeding efforts in India led to the adoption of tomato cultivars carrying the resistance gene Ty-2. However, it has been observed recently that such cultivars/hybrids are susceptible to begomoviruses. This requires the identification of additional or new sources of resistance against ToLCBaV. The present study was undertaken to assess the effectiveness of several Ty genes in providing resistance against infection by ToLCBaV. The kinetics of virus multiplication in different Ty resistance gene stocks of tomato were estimated and compared using quantitative PCR data. Accumulation of viral genomic units and symptom severity were lower in tomato lines carrying Ty-3 and Ty-2 + Ty-3 compared with those carrying Ty-2 alone. All tested lines carrying Ty-2 showed typical tomato leaf curl disease symptoms. Tomato lines carrying Ty-2 + ty-5 and ty-5 + Ty-6 combinations had a significantly higher disease severity index and viral genomic units compared to those carrying Ty-3 and Ty-2 + Ty-3 at 30 days postinoculation. The accumulation level of ToLCBaV genomic units serves as a good indicator for resistance selection along with other parameters of disease. We present here a comprehensive overview of the effectiveness of Ty-2, Ty-3, and ty-5 alone as well as the combinations Ty-2 + Ty-3 and Ty-2 + ty-5 against ToLCBaV.     

Development and characterization of interspecific hybrids of Trifolium alexandrinum×T. apertum using embryo rescue

This is the first report on the development of interspecific hybrids between Trifolium alexandrinum and T. apertum using embryo rescue and characterization of F₁ plants. T. apertum was used as the male parent and T. alexandrinum as the female parent. Development of interspecific hybrids under natural conditions is not successful and so embryo rescue was attempted. Of the several combinations tried, pollination 2 days after emasculation and embryos rescued 11 days after pollination was found to be the best. For embryo culture, EC3 medium consisting of MS basal supplemented with 2.3 μM kinetin and 3% sucrose was used. Germinated embryos were transferred to LSP3 medium 25 days after inoculation wherein most of the cultures showed multiple shoots that were split and subcultured on RL1 medium for rooting. After hardening, about 75% of hybrids were successfully transferred to the field. The hybrids, in general, showed morphological traits intermediate between the two parents; however, a few hybrids showed better growth than either parent. Some F₁ plants were almost 3 weeks later in flowering than the female parent. Pollen fertility among these plants ranged from 78 to approximately 100%. Chromosomal associations at diakinesis and isozyme banding patterns for acid phosphatase (ACP), superoxide dismutase (SOD) and peroxidase also confirmed the hybrid nature of the plants.     

Classification of features selected through Optimum Index Factor (OIF) for improving classification accuracy

The present investigation was performed to determine if the features selected through Optimum Index Factor (OIF) could provide improved classification accuracy of the various categories on the satellite images of the individual years as well as stacked images of two different years as compared to all the features considered together. Further, in order to determine if there occurs increase in the classification accuracy of the different categories with corresponding increase in the OIF values of the features extracted from both the individual years’ and stacked images, we performed linear regression between the producer’s accuracy (PA) of the various categories with the OIF values of the different combinations of the features. The investigations demonstrated that there occurs significant improvement in the PA of two impervious categories viz. moderate built-up and low density built-up determined from the classification of the bands and principal components associated with the highest OIF value as compared to all the bands and principal components for both the individual years’ and stacked images respectively. Regression analyses exhibited positive trends between the regression coeffi- cients and OIF values for the various categories determined for the individual years’ and stacked images respectively signifying the prevalence of direct relationship between the increase in the information content with corresponding increase in the OIF values. The research proved that features extracted through OIF from both the individual years’ and stacked images are capable of providing significantly improved PA as compared to all the features pooled together.     

Characterization and identification of leaf morphology of Populus deltoides Bartr.clones

Leaves are of fundamental importance to plants,representing their facility to generate power and are the sensing units of plants towards the environment.An attempt was made to characterize and compare the variations of leaf morphology of various Populus deltoides Bartr.clones by studying the winter buds and other leaf parameters of fully developed leaves.To achieve these objectives,forty-three exotic and indigenous clones of P.deltoides Bartr.were evaluated for different parameters.On the basis of various morphological characteristics the results reveal that each clone has a distinct color pattern of leaves.Different colors observed in these clones varied from light green through green to dark green.Two distinct lengths of the leaf apex were found,i.e.,short and long; as well both acuminate and acute apex types were found.Erratic distribution of serration of leaves was also found.In this study,the morphological traits of leaves provided discriminatory grounds for separating various populations of P.deltoides Bartr.clones.Winter bud studies indicate that different clones vary considerably with regard to shape,color,shape of leaf scars and exudation.     

Biochemical Alterations in the Blood Plasma of Rats Associated with Hepatotoxicity Induced by Eupatorium adenophorum

Eupatorium adenophorum (Crofton weed), a native of Central America, has appeared as a major weed in several areas in different parts of the world. Horses that eat this plant are poisoned on prolonged exposure. Toxicity due to consumption of this plant by other grazing animals is not clear. Administration of freeze-dried leaf powder to mice results in hepatotoxicity. Earlier attempts to produce toxicity in rats using the leaves of this plant were not successful. In the present study, administration of oven-dried E. adenophorum leaves collected at the flowering stage elicited hepatotoxicity in rats. The affected animals had a marked increase in the concentration of plasma bilirubin and in the activities of 5-nucleotidase, alkaline phosphatase, aspartate aminotransferase, alanine aminotransferase and lactate dehydrogenase. There were no significant differences in plasma creatinine, urea or total protein values in the affected animals compared to controls. The livers of the affected animals had focal areas of necrosis throughout the parenchyma and hepatocytes showed megalocytosis. The bile ducts were dilated and the epithelium showed degenerative to necrotic changes. The alterations in bilirubin, enzymes and histopathological changes imply cholestasis and liver injury.