Growth and Mineral Nutrition of the Chickpea ( Cicer arietinum L.)-Rhizobia Symbiosis under Water Deficit

ABSTRACT The effect of the water deficit on the fresh and dry weight in the various parts of the plant and on several mineral processes in different symbiotic combinations for the chickpea (Cicer arietinum L.) varieties was studied. The experiment was undertaken in the greenhouse during five weeks.Seedlings were separately inoculated with a suspension of three rhizobia strains and were grown under water deficit (50% of field capacity). Our results showed that the inoculation with the adequate rhizobia may improve the chickpea dry weight by improving the nodules weight, increase NR activity and more K+ accumulation under water deficit. Generally, MC0415 (S1) strain gives the best results, particularly in the dry weight nodules (5% of reduction) and in parallel higher NR activity was notedinthenodule systems (0.8±0.02 μmol NO2-g FW-1h-1) with the combination V46-S1. We note a strong correlation between the dry weights of the various parts of the plantand the studied variables (NRA, Na+, andK+).

In vitro response of date palm (Phoenix dactylifera L) to K/Na ratio under saline conditions

BACKGROUND: Salinity is a serious factor limiting the productivity of agricultural plants. One of the potential problems for plants growing under saline conditions is the inability to up take enough K+. The addition of K+ may considerably improve the salt tolerance of plants grown under salinity. It is assumed that increasing the K+ supply at the root zone can ameliorate the reduction in growth imposed by high salinity. The present study aims to determine whether an increase in the K/Na ratio in the external media would enhance the growth of date palm seedlings under in vitro saline conditions. METHODS: Date palm plants were grown at four concentrations of Na + K/Cl (mol/m³) with three different K/Na ratios. The 12 salt treatments were added to modified MS medium. The modified MS medium was further supplemented with sucrose at 30 g/l. RESULTS: Growth decreased substantially with increasing salinity. Growth expressed as shoot and root weight, enhanced significantly with certain K/Na ratios, and higher weight was maintained in the presence of equal K and Na. It is the leaf length, leaf thickness and root thickness that had significant contribution on total dry weight. Na+ contents in leaf and root increased significantly increased with increasing salinity but substantial decreases in Na+ contents were observed in the leaf and root with certain K/Na ratios. This could be attributed to the presence of a high K+ concentration in the media. The internal Na+ concentration was higher in the roots in all treatments, which might indicate a mechanism excluding Na+ from the leaves and its retention in the roots. K/Na ratios up to one significantly increased the leaf and root K+ concentration, and it was most pronounced in leaves. The K+ contents in leaf and root was not proportional to the K+ increase in the media, showing a high affinity for K+ uptake at lower external K+ concentrations, but this mechanism continues to operate even with high external Na+ concentrations. CONCLUSION: Increasing K/Na ratios in the growing media of date plam significantly reduced the absorption of Na+ less than 200 mM and also balance ions compartmentalization.

EXPERIMENTAL. STUDY ON THE CHANGE OF K~+/Na~+ Mg~(2+)/Ca~(2+)、Zn~(2+)/Cu~(2+)RATIO IN CARDIAC MUSCLE WITH ACUTE MYOCARDIAL IN FARCTION / 中国法医学杂志

Using the animal model of acute myocardial infarction of rabbit after left coronary artery ligation, the authors studied the reltionship between the change of myocardial K~+/Na~+ ,Mg~(2+)/Ca~(2+), and Zn~(2+)/Cu~(2+) ratio and the time after acute myocardial infarction. The results demonstrated that. (1)the K+/Na~+ and Mg~(2+)/Ca~(2+)ratio dropped with prolongation of time myocardial ischemia. There was significant (P0.05)difference of Zn~(2+)/Cu~(2+) ratio between the experimental groups and the control group, but Zn~(2+)/Cu~(2+) ratio showed a tendency of dropping with prolongation of time of ischemia in the experimental group. At 120 min of myocardial ischemia,the Zn~(2+)/Cu~(2+) ratio was abour 1/2 as those at 15min, 30min, and 60min(P

THE SIGNIFICANCE OF DETERMINING K~+/N_a ~+ RATIO FOR TIMING OF THE WOUNDS / 中国法医学杂志

For the purpose of timing of wounds,the measurement of K~+/Na~+ ratio of 36specimens of wister rat's muscles taken from the local burn area by the atomicabsorption spcetrophometry was carried out.The results showed that K~+/Na~+ ratio in specimens of burn formed 15,30,60minutes before death and 20 minutes after death reduced 47～82%(mean 71%),56～89%(mean 77%),69～94%(mean 86%)and 4～38%(mean 27%)respectively ascompared with the control muscles.Reduction rate of K~+/Na~+ ratio in ante-mortem group was more obvious than the postmortem ones.With the prolongationof the antemortem interval,the reduction of K~+/Na~+ ratio becomes more marked.We believe that this method is a simple and reliable method in timing woundsand it is valuable in forensic medicine practice.