Triacontanol stimulates nitrogen-fixation,enzyme activities,photosynthesis, crop productivity and quality of hyacinth bean (Lablab purpureus L.)

Hyacinth bean (Lablab purpureus L.) serves as a good source of vegetable proteins in human diet, and its seeds and pods contain as much as 20–28% protein. The bean contains tyrosinase enzyme, which has potential use for the treatment of hypertension. However, plant biological yield appears to be comparatively low in Aligarh soil in this region of India (Western Uttar Pradesh). A hypothesis was designed to address whether foliar application of triacontanol (TRIA) could enhance the crop productivity as well as crop quality. TRIA is known to be a potent plant growth promoting substance for many agricultural and horticultural crops. The hyacinth bean plants grown in soil containing pots, were sprayed with five concentrations of TRIA (10⁻⁰ (Control), 10⁻⁸, 10⁻⁷, 10⁻⁶ and 10⁻⁵ M) at 15-day intervals. The plant fresh and dry weights, leaf-area, number and dry weight of nodules per plant, total chlorophyll and carotenoid content, nitrate reductase activity, carbonic anhydrase activity, nodule-nitrogen content, leghemoglobin content and leaf N, P, K and Ca contents were analyzed at 60, 90 and 120 days after sowing (DAS). Net photosynthetic rate, transpiration rate and stomatal conductance were measured only at 90 DAS. The protein content plus carbohydrate and tyrosinase activity were analyzed in the seeds. Foliar spray of 10⁻⁶ M TRIA significantly stimulated most of the studied attributes. At the highest concentration (10⁻⁵ M TRIA), values of all attributes were significantly decreased at all three stages. For example, 10⁻⁶ M TRIA increased seed-yield and -protein content by 56.3 and 14.5%, respectively when compared to unsprayed plants. TRIA also stimulated the activity of tyrosinase when compared to the control plants.     

Lake Naivasha (Kenya,East Africa) fishery and its management together with a note on the food habits of fishes

The Lake Naivasha fishery is constituted by three introduced species, Sarotherodon leucostictus, Tilapia zillii and Micropterus salmoides. No indigenous species are now found in the lake. S. spilurus niger, another introduced species, and hybrids of S. s. niger × S. leucostictus, abundant in 1961, have almost completely disappeared.The annual catch of Sarotherodon-Tilapia and M. salmoides between 1968 and 1974 ranged from 109·2 to 1479·6 metric tons and 7·9 to 471·9 metric tons respectively.S. leucostictus is a bottom feeder (chironomid larvae 64°24%, detritus 20·58%), T. zillii feeds on aquatic macrophytes (76·62%) and M. salmoides feeds almost exclusively on crayfish (78·25%). A major portion of the fish food present in the lake is left unused.The yield, which has progressively declined since 1968, could be increased considerably by introducing certain management measures. These are discussed.     

Impact of wheat-Leymus racemosus added chromosomes on wheat adaptation and tolerance to heat stress

Adaptation of wheat (Triticum aestivum L.) to high temperatures could be improved by introducing alien genes from wild relatives. We evaluated the responses of wheat-Leymus racemosus chromosome introgression lines to high temperature to determine their potentiality for developing improved wheat cultivars. Introgression lines and their parent Chinese Spring were evaluated in a growth chamber at the seedling stage and in the field at the reproductive stage in two heat-stressed environments in Sudan. Optimum and late planting were used to ensure exposure of the plants to heat stress at the reproductive stage. The results revealed the impact of several Leymus chromosomes in improving wheat adaptation and tolerance to heat. Three lines possessed enhanced adaptation, whereas two showed high heat tolerance. Two addition lines showed a large number of kernels per spike, while one possessed high yield potential. Grain yield was correlated negatively with the heat susceptibility index, days to heading and maturity and positively with kernel number per spike and triphenyl tetrazolium chloride assay under late planting. The findings suggest that these genetic stocks could be used as a bridge to introduce the valuable Leymus traits into a superior wheat genetic background, thus helping maximize wheat yield in heat-stressed environments.     

Characterization of Embryonic Stages through Variations in the Egg＇s Contents in Spodoptera fitura

This paper describes the embryonic development of the common cutworm Spodoptera litura （Fabricius） （Lepidoptera： Noctuidae） which is divided into eight embryonic stages, through variations in the egg＇s contents. Experiments were conducted on the eggs ofS. litura under laboratory conditions. The highest concentration of the protein （min.-max.： 32-! 40 lag/egg） and the lowest of the carbohydrate （min.-max.： 3.0-44.0 lag/egg） were obtained; similarly, the DNA content was smaller （min.-max.： 1.0-38.2 lag/egg） than the RNA （min.-max.： 9.2-360.0 lag/egg） throughout the embryogenesis. Three peaks of ecdysteroid titre were observed which were responsible for appearance of particular events during embryogenesis. The last highest peak of 400_＋33.4 lag/egg was appeared at 84 h after oviposition when larva was ready to hatch. Therefore, it is concluded that eight embryonic stages in S. litura were characterized by fluctuation in the egg＇s contents, which were responsible for gradual-progressive embryonic development. The egg-larval development did not show a normal distribution of embryonic developmental-time.     

Effect of dry and wet storage at cool temperatures on the post-harvest performance of Ranunculus asiaticus L. flowers

A study was undertaken to assess the effect of different storage temperatures on senescence and postharvest performance of isolated flowers of Ranunculus asiaticus L.. The main aim of the work was to develop a cost-effective storage protocol to reduce the postharvest losses and to bring out the transportation of cut flowers of R. Asiaticus. The flowers were subjected to two different storage treatments, dry storage and wet storage, and their postharvest performance was compared under laboratory conditions. For this purpose, the buds were harvested at 8:00 AM at loose bud stage (Stage II of flower development). The harvested buds were cut to a uniform size of 15 cm and processed for dry or wet storage. For dry storage, the buds were packed after wrapping them in moistened filter papers and kept at 5°C and 10°C. For wet storage, the buds were held in distilled water in separate glass beakers kept at 5°C and 10°C, respectively. A separate set of buds each for dry and wet storage was kept at room temperature (15±2)°C. After 72 h storage, the buds were kept at room temperature in distilled water. The average life of an individual flower that opened fully was about 4–5 days. The buds kept under wet storage at 5°C and 10°C for 72 h maintained their premature status, while the buds held at room temperature for 72 h generally bloomed. All the buds stored dry maintained their premature status irrespective of storage temperature. Storage of buds for 72 h at 5°C, followed by transferring to distilled water improved the longevity by about 5 to 6 days. Cold storage treatment before transferring to holding solution improved floral diameter, membrane integrity besides maintaining higher fresh and dry mass of flowers, sugar content, soluble proteins, and phenols. Our results suggested that wet and dry storage of premature buds of R. asiaticus for 72 h at 5°C, followed by placing them in distilled water, improved the cut flower longevity and can be used as effective postharvest storage treatments for this beautiful cut flower.     

Effects of dietary protein levels on growth,feed utilization,protein retention efficiency and body composition of young <Emphasis Type="Italic">Heteropneustes fossilis</Emphasis> (Bloch)

An 8-week growth trial was conducted to assess the effect of dietary protein on growth, feed utilization, protein retention efficiency, and body composition of young Heteropneustes fossilis (10.02 ± 0.09 g; 9.93 ± 0.07 cm). Isocaloric (4.15 kcal g⁻¹, GE) diets with varying levels of protein (25, 30, 35, 40, 45, and 50% of the diet) were fed near to satiation to triplicate groups of fish. Optimum dietary protein was determined by analyzing live weight gain (LWG%), feed conversion ratio (FCR), protein efficiency ratio (PER), specific growth rate (SGR%), and protein retention efficiency (PRE%) data. Maximum LWG% (167), best FCR (1.42), PER (1.75), SGR (1.76), and PRE (31.7%) were evident in fish fed 40% protein diet (Diet 4). Body protein data also supported the above level. However, second-degree polynomial regression analysis of the above data indicated that inclusion of dietary protein in the range of 40–43% is optimum for the growth of young H. fossilis.     

Post-translational modifications in effectors and plant proteins involved in host–pathogen conflicts

Molecular interplay between two species is largely driven by protein–protein interactions and protein modifications that set the pace of co-evolution in these species. During host–pathogen interactions, proteins involved in virulence and defence impart tempospatial dynamic post-translational modifications (PTMs) to gain advantage for the causative species. Pathogens mainly cause disease in plant hosts by secreting elicitors (peptides and small molecules) or proteins in the inter- and intracellular space of host cells. These pathogen proteins have evolved a wide array of sophisticated mechanisms to manipulate host responses, including resistance. Through a set of diverse events ranging from PTMs to post-translational oligomerization, these proteins are able to enhance virulence and suppress the otherwise elaborate plant immune system. Similarly, PTMs adapted by host proteins often lead to the activation of a robust defence response. Insights into the PTMs of pathogen and host proteins are therefore germane to the understanding of the co-evolutionary arms race. This review summarizes the characterization of PTMs in pathogen effectors and their target host proteins. Based on this, a metaphorical view of host–pathogen conflicts is proposed, where PTMs act as molecular pivots in a 3D combinatorial game model – a novel abstraction of the arms race, where these molecular pivots restore the balance of competition between the two organisms.     

Improving nodulation,growth and yield of Cicer arietinum L. through bacterial ACC-deaminase induced changes in root architecture

Bacteria containing ACC-deaminase in the vicinity of roots may influence plant growth by modifying root architecture through their potential to regulate ethylene synthesis in plant roots. Approximately 138 isolates capable of utilizing ACC as the sole source of N were isolated from the rhizosphere soil of chickpea (Cicer arietinum L.) plants. Under axenic conditions, some rhizobacterial isolates were highly effective in increasing root length (up to 2.08 fold), number (up to 3.7 fold) and length (up to 3.9 fold) of lateral roots, and root biomass (up to 83%) of chickpea as compared to uninoculated control. Serratia proteamaculans strain J119 was found to be the most effective plant growth promoting rhizobacterium (PGPR) in improving root and shoot growth, nodulation and grain yield of chickpea as compared to respective controls in growth pouches, pot and field trials. A highly significant direct correlation (r = 0.99) was observed between number of lateral roots under axenic conditions (jar trial) and number of nodules per plant in pot and field trials. Interestingly, S. proteamaculans J119 also exhibited highest ACC-deaminase activity in addition to root colonization compared to other tested strains. The results of this study demonstrated that changes in root growth and architecture (particularly lateral roots) as a result of inoculation with PGPR containing ACC-deaminase are crucial for improving growth, yield and nodulation of chickpea under field conditions.