The effect of four new Frankia isolates on growth and nitrogenase activity in clones of Alnusrubra and Alnussinuata

1984 ◽  
Vol 14 (5) ◽  
pp. 701-706 ◽  
Author(s):  
Carolyn V. Carpenter ◽  
Linda R. Robertson ◽  
John C. Gordon ◽  
David A. Perry

Two clones of red alder (Alnusrubra Bong) and two clones of Sitka alder (Alnussinuata (Regel) Rydb) were inoculated with four new Frankia isolates. The endophytes included a red and a Sitka alder isolate from Vancouver Island, British Columbia, and a red and a Sitka alder isolate from Mount Hood National Forest, Oregon. All inoculated ramets were well nodulated and had an active nitrogenase system as measured by the acetylene reduction assay. For the inoculated red alder clones, host genotype had a significant effect on stem height and root weight. None of the growth parameters was affected by endophyte strain or by clone–endophyte interaction. For Sitka alder clones, host genotype affected all growth variables. While endophyte strain had no effect on plant growth, clone–endophyte interaction occurred with stem height and leaf weight. Conversely, acetylene reduction values were not affected by clone or clone–endophyte interaction in either species. In red alder, acetylene reduction values were significantly affected by endophyte strain showing both inter- and intra-species variations. In Sitka alder, endophyte strain did not affect acetylene reduction values. The results indicate that both host genotype and endophyte may affect the efficiency of host–endophyte symbioses.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fatemeh Ahmadi ◽  
Abbas Samadi ◽  
Ebrahim Sepehr ◽  
Amir Rahimi ◽  
Sergey Shabala

AbstractMedicinal plants represent a valuable commodity due to beneficial effects of their natural products on human health, prompting a need for finding a way to optimize/increase their production. In this study, a novel growing media with various perlite particle size and its mixture with peat moss was tested for hydroponic-based production of Echinacea purpurea medicinal plant under greenhouse conditions. The plant growth parameters such as plant height, total fresh leave weight, fresh root weight, total biomass, total chlorophyll, leaf area, and essential oil compositions were assessed. Perlite particle size in the growing media was varied from very coarse (more than 2 mm) to very fine (less than 0.5 mm), and the ratio between perlite and peat moss varied from 50:50 v/v to 30:70 v/v. In addition, two nitrate (NO3−) to ammonium (NH4+) ratios (90:10 and 70:30) were tested for each growing media. The medium containing very fine-grade perlite and 50:50 v/v perlite to peat moss ratio was found to be most optimal and beneficial for E. purpurea performance, resulting in maximal plant height, fresh and dry weight, leaf surface area, and chlorophyll content. It was also found that an increase in NO3−/NH4+ ratio caused a significant increase in plant growth parameters and increase the plant essential oil content. The major terpene hydrocarbons found in extract of E. purpurea with the best growth parameters were germacrene D (51%), myrcene (15%), α-pinene (12%), β-caryophyllene (11%), and 1-Pentadecene (4.4%), respectively. The percentages of these terpene hydrocarbons were increased by increasing of NO3−/NH4+ ratio. It can be concluded that decreasing the perlite particle size and increasing the NO3−/NH4+ ratio increased the plant growth parameters and essential oil compositions in E. purpurea.


2016 ◽  
Vol 8 (1) ◽  
pp. 284-289
Author(s):  
S. Kanimoli ◽  
K. Kumar

The present study was carried out to evaluate the nitrogen fixing ability of diazotrophs isolated from the rhizosphere soils of rice which were grown in three different rice growing systems. A total of hundred and ten isolates obtained were subjected to Acetylene Reduction Assay (ARA) and ninety eight isolates recorded significant amount of nitrogenase activity in a range of 185.73 to 3794.55 nmoles of ethylene mg of protein-1 h-1. The highest nitrogenase activity was recorded by Derxia (3794.55 nmoles of ethylene mg of protein-1 h-1) isolated from Trichy (lowland). Among the three different rice production systems, isolates obtained from lowland rice (Derxia – 3794.5 nmoles of ethylene mg of protein-1 h-1) recorded higher nitrogenase activity followed by Aerobic (Pseudomonas - 2194.89 nmoles of ethylene mg of protein-1 h-1) and SRI (Azotobacter - 1971.85 nmoles of ethylene mg of protein-1 h-1) rice isolates. The results revealed marked variation in the ARA of the diazotrophic isolates obtained from lowland, SRI and Aerobic rice. The nitrogenase activity of diazotrophs from rice fields have been reported earlier but the nitrogenase activity of diazotrophs from three different rice production systems from various parts of Tamil Nadu is reported for the first time from India.


1983 ◽  
Vol 10 (1) ◽  
pp. 26-29 ◽  
Author(s):  
P. T. C. Nambiar ◽  
P. J. Dart

Abstract Acetylene reduction assay, used to measure nitrogenase activity of legume root nodules, is influenced by environmental factors, which limit its application. The effects of some of the environmental factors on acetylene reduction by groundnut root nodules are described. The activity was nonlinear during the first hour of incubation. Assay temperature above 25 C decreased the activity. Washing the nodulated roots prior to the assay also decreased the activity. The activity was influenced by light intensity, soil moisture, and moisture content in the incubation bottle. Diurnal fluctuation with one maximum and one minimum activity period during a 24 hour cycle was observed. Nitrogenase activity was higher during the postrainy season compared to that of the rainy season. A virginia cultivar Kadiri-71 had higher nitrogenase activity than a dwarf valencia cultivar, MH 2.


2021 ◽  
Vol 41 ◽  
pp. 67-74
Author(s):  
Lukito Hasta Pratopo ◽  
Ahmad Thoriq ◽  
Rizky Mulya Sampurno ◽  
I Made Joni

Dissolved oxygen in water is one of the factors affecting plant growth in the hydroponic nutrient film technique system. The fine bubble generator technique allows the provision of high dissolved oxygen levels in water with fine bubble size and prolonged water existence. The experiment was conducted to observe the effect of fine bubbles on choy sum plant growth. Plant growth parameters including leaf length (Pd), leaf width (Ld), plant height (Tt), number of leaves (Jd), and root weight (Ba) were measured every two days while the total plant weight was measured at harvest. Nutritional water quality and microclimate were controlled using internet of things (IoT) based sensors every 5 minutes. The research data were processed using descriptive analysis. The results showed that the use of fine bubbles increased the electrical conductivity (EC), pH, and total dissolved solids (TDS). On the contrary, the nutrient solution’s temperature increased, thus reducing the total dissolved oxygen content. The yields showed that the choy sum plant growth using fine bubbles application weighed 1.71 kg (5 samples) better than the control 1.35 kg.


2021 ◽  
Vol 58 (04) ◽  
pp. 1291-1299
Author(s):  
Muhammad Usman Afzal

Citrus is known as a major fruit due to its high nutritional value and adaptability in tropical and sub-tropical regions. Among diseases, citrus dieback is one of the most threatening diseases in which overall plant growth is reduced. Major causes are Colletotrichum gloeosporioides and citrus nematode (Tylenchulus semipenetrans) with 15-35% losses all over the world. Plant material was established adopting sanitary measures in earthen pots (12-inch diameter). Fresh culture of C. gloeosporioides and T. semipenetrans was prepared for the inoculation by following the standard procedures. In the first set, rootstocks were inoculated with 200mL of water having spore suspension of C. gloeosporioides while in in the second set, inoculation of T. semipenetrans was done by using 45 mL of water suspension having 2000 freshly hatched juveniles per pot, while at the rate of 1 × 107 spores/mL per plant. In the third set, the interaction of C. gloeosporioides and T. semipenetrans was studied by inoculating selected citrus rootstocks by both pathogens. After four months of inoculation, data were recorded on plant disease index (PDI) along with plant growth parameters (root weight, shoot weight, shoot weight, shoot length and number of leaves). Trifoliate orange and cox mandarin hybrid showed resistance against the development of T. semipenetrans while rough lemon, C-35 Citrange and sour orange were found susceptible. There was a significant difference in plant growth parameters between inoculated and healthy plants. Root weight and shoot weight decreased by 8.98g and 11.53g, while root length and shoot length decreased by 7.29cm and 13.5cm respectively as compared to control treatments in most susceptible rootstocks. Per cent Branch Infection (PBI) and per cent Disease Index (PDI) were maximum (71.52, 37) per cent on rough lemon respectively. Results regarding combined inoculation of C. gloeosporioides and T. semipenetrans showed that there was a significant difference in plant growth parameters between inoculated and healthy plants. In rough lemon, Root weight and shoot weight decreased by 13.86 and 20.57g respectively in diseased and healthy plants. Root length and shoot length decreased by 8.37 and 20.04cm respectively as compared to control treatments in most susceptible rootstocks. Overall results depicted that inoculation of both pathogens reduced plant growth more severely as compared to their individual application.


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