Growth and Symbiotic Performance of Chickpea (Cicer arietinum) Cultivars under Saline Soil Conditions

The present study was conducted to investigate growth and symbiotic performance of selected salt tolerant chickpea (Cicer arietinum) cultivars under arid saline soil conditions. Plants were grown in saline soil of Syrdarya province, Uzbekistan. The results showed that the growth and nodulation of chickpea cultivars Uzbekiston-32, Xalima, Miroz, Flip 1-33 and CIEW 45 were much better under saline conditions compared other chickpea cultivars. Inoculation of salt tolerant chickpea cultivars with M. ciceri IC53 significantly increased numbers of nodules on the roots (300%), shoot and root dry weight (27%), pod numbers (28%) and yield (23%). The above results revealed that for achieving the highest symbiotic effectiveness under salinity conditions plant cultivars have to be taken into account. It could be suggested that cultivation of salt tolerant cultivars with its symbiotic partners could be an effective selection technology to overcome the problem of soil salinity. Key words: Chickpea, Cultivars, Salinity, Mezorhizobium ciceri, and Nodulation

Microbial strategies for the improvement of legume production in hostile environments

Various biotic and abiotic factors limit crop productivity, affecting nearly 1 billion people around the world. Malnutrition is recognized as the world’s most serious health problem, while agricultural development is considered as the most effective sector in reducing hunger and poverty, through improvements in crop productivity..

Soybean Nodulation Response to Cropping Interval and Inoculation in European Cropping Systems

To support the adaption of soybean [Glycine max (L) Merrill] cultivation across Central Europe, the availability of compatible soybean nodulating Bradyrhizobia (SNB) is essential. Little is known about the symbiotic potential of indigenous SNB in Central Europe and the interaction with an SNB inoculum from commercial products. The objective of this study was to quantify the capacity of indigenous and inoculated SNB strains on the symbiotic performance of soybean in a pot experiment, using soils with and without soybean history. Under controlled conditions in a growth chamber, the study focused on two main factors: a soybean cropping interval (time since the last soybean cultivation; SCI) and inoculation with commercial Bradyrhizobia strains. Comparing the two types of soil, without soybean history and with 1-4 years SCI, we found out that plants grown in soil with soybean history and without inoculation had significantly more root nodules and higher nitrogen content in the plant tissue. These parameters, along with the leghemoglobin content, were found to be a variable among soils with 1-4 years SCI and did not show a trend over the years. Inoculation in soil without soybean history showed a significant increase in a nodulation rate, leghemoglobin content, and soybean tissue nitrogen concentration. The study found that response to inoculation varied significantly as per locations in soil with previous soybean cultivation history. An inoculated soybean grown on loamy sandy soils from the location Muncheberg had significantly more nodules as well as higher green tissue nitrogen concentration compared with non-inoculated plants. No significant improvement in a nodulation rate and tissue nitrogen concentration was observed for an inoculated soybean grown on loamy sandy soils from the location Fehrow. These results suggest that introduced SNB strains remained viable in the soil and were still symbiotically competent for up to 4 years after soybean cultivation. However, the symbiotic performance of the SNB remaining in the soils was not sufficient in all cases and makes inoculation with commercial products necessary. The SNB strains found in the soil of Central Europe could also be promising candidates for the development of inoculants and already represent a contribution to the successful cultivation of soybeans in Central Europe

Bacteria-inducing legume nodules involved in the improvement of plant growth, health and nutrition

Bacteria-inducing legume nodules are known as rhizobia and belong to the class Alphaproteobacteria and Betaproteobacteria. They promote the growth and nutrition of their respective legume hosts through atmospheric nitrogen fixation which takes place in the nodules induced in their roots or stems. In addition, rhizobia have other plant growth-promoting mechanisms, mainly solubilization of phosphate and production of indoleacetic acid, ACC deaminase and siderophores. Some of these mechanisms have been reported for strains of rhizobia which are also able to promote the growth of several nonlegumes, such as cereals, oilseeds and vegetables. Less studied are the mechanisms that have the rhizobia to promote the plant health; however, these bacteria are able to exert biocontrol of some phytopathogens and to induce the plant resistance. In this chapter, we revised the available data about the ability of the legume nodule-inducing bacteria for improving the plant growth, health and nutrition of both legumes and nonlegumes. These data showed that rhizobia meet all the requirements of sustainable agriculture to be used as bio-inoculants allowing the total or partial replacement of chemicals used for fertilization or protection of crops

Alleviation of Salt Stress in Legumes by Co-inoculation with Pseudomonas and Rhizobium

Abstract Numerous studies have shown that soil salinity decreases nodulation and dramatically reduces N 2 fi xation and nitrogenase activity of nodulated legumes. Thus, the development of salt-tolerant symbioses is an absolute necessity to enable cultivation of leguminous crops in salt-affected soils. Dual inoculation of legumes with plant growth-promoting rhizobacteria (PGPR) and rhizobia has been reported to increase the number of nodules compared to those formed by a rhizobial strain alone. The production of IAA by Pseudomonas strains represents a benefi cial mechanism that promoted enlargement of root system and thereby further enhanced nutrient uptake, nodulation, and shoot growth of leguminous plants. When PGPR are able to alleviate salt stress experienced by the plant, more nodules might develop into nitrogen-fi xing ones, thereby enabling the plant to obtain part of its nitrogen from the atmosphere. Co-inoculation techniques could be a new approach to increas