The incompatibility system and relative ectomycorrhizal performance of monokaryons and reconstituted dikaryons of Laccaria bicolor

1988 ◽  
Vol 66 (2) ◽  
pp. 289-294 ◽  
Author(s):  
Bradley R. Kropp ◽  
J. A. Fortin

The incompatibility system of four Laccaria bicolor collections was studied and found to be bifactorial with multiallelic mating type factors. One of the collections studied was a biological species of L. bicolor that was intersterile, but morphologically identical, with the others. Seedling growth parameters and ectomycorrhiza formation were measured after inoculation with (i) four sibling mating type monokaryons of a collection from Canada and from Sweden; (ii) four dikaryons formed by crossing the two compatible mating type pairs within each of these collections; and (iii) 16 dikaryons formed by crossing each mating type monokaryon from Canada and Sweden in all possible combinations. Each seedling growth parameter showed significant differences resulting from inoculation with different cultures. Ectomycorrhizal formation was also different depending on the culture used as inoculum. Possibilities for using the differences among cultures in studies of the genetics, physiology, and morphogenesis of the ectomycorrhizal symbiosis are discussed. The possibility of creating improved strains of ectomycorrhizal fungi for use in forest management is also discussed.

2021 ◽  
Vol 25 (6) ◽  
pp. 969-975
Author(s):  
M.K. Peter ◽  
SIN Agera ◽  
J.I. Amonum

This study investigated the effects of potting media on seed germination and early seedling growth of Pterocarpus erinaceus Poir at the Forestry Nursery in Jos, Nigeria. Using Completely Randomized Design (CRD) with three replicates, laboratory-tested soil samples, top soil, sharp sand, sharp sand + top soil, sharp sand + top soil + cow dung and sharp sand + top soil + poultry droppings were used in various combinations to assess the growth parameters of P. erinaceus (germination percentage, emergence, plant height, number of leaves, length of leaves and stem diameter) for 12 weeks. Descriptive and inferential statistics were employed to analyze collected data. Result indicated that sharp sand + top soil + poultry droppings had the highest nitrogen concentration (2.19%), sharp sand + top soil + cow dung (2.07%), sharp sand + top soil (1.50%), top soil (0.72%) and Sharp sand (0.38%). Potting media with poultry droppings recorded an overall higher percentage germination of 42.9% by the end of the germination period. Analysis of variance (ANOVA) of collected data on combined soil aggregate on growth parameters indicated a significant (p<0.05) difference in plant height, number of leaves, leaf length and stem diameter. Potting with poultry dropping gave the best potting media growth results when compared to other treatments that enhanced seed germination and seedling growth of P. erinaceus. This superior observation of the poultry droppings incorporated potting mixtures over the cow dung provides an outstanding potentials to enhance P. erinaceus plantation establishment. Consequently, recommended for raising seedlings in the nursery as well as ensuring sustainable management.


Author(s):  
Gamze Kaya

The study aimed to evaluate the use of germination indices as a screening tool for salinity tolerance during germination and early seedling growth of pepper cultivars, and to distinguish the potential for genetic responses to salt tolerance. In the study, the seeds of seven pepper cultivars were germinated at increasing NaCl levels of 5, 10, 15 and 20 dS/m and distilled water as the control treatment for 14 days. Germination percentage (GP), mean germination time (MGT), germination index (GI), germination stress tolerance index (GSTI), seedling length (SL), seedling fresh weight (SFW) and vigor index (VI) were investigated. Results showed that germination percentage decreased with increasing NaCl levels while the highest germination percentage at 20 dS/m was 92% in BT Burdem with no significant reduction. Seedling growth of pepper cultivars was severely inhibited by increasing salinity stress. SFW was depressed depending on reduction in SL due to increasing NaCl. BT-Burli and BT İnce Sivri were the most tolerant cultivars to NaCl and they were used for genetic resources towards salinity. Seedling growth was much more sensitive to salinity than germination because of the highest percent reduction in seedling growth parameters. Among the parameters, GSTI gave the highest significant correlation coefficient with SL and SFW; indicating that it would be useful for estimating seedling growth. It was concluded that genotypic variation was observed among pepper cultivars for salinity tolerance and GSTI could be used for a predictor for salinity tolerance.


2021 ◽  
Vol 25 (8) ◽  
pp. 1547-1550
Author(s):  
O.A. Majekodunmi ◽  
I.O. Abiola ◽  
A.M. Aderemi ◽  
J.O. Adedipe ◽  
O.G. Ogunwale ◽  
...  

This study investigated the effect of sowing media on the seed germination and subsequent seedling growth of Senna fistula L. Treatments were T1 (Top soil), T2 (River sand), T3 (Grinded coconut husk) and T4 (weathered sawdust), replicated two times for seed germination. The treatments were arranged in a Completely Randomized Design (CRD) and the data generated was subjected to analysis of variance (ANOVA) at 5% level of significance, while mean separation where appropriate was done using Least Significant Difference (LSD). The different sowing media used had positive effect on the seed emergence, the seeds planted in river sand had the highest emergence percentage of 70%. The different sowing media used did not have any significant effect on the vegetative growth parameters, statistically, they had same effect on the parameters measured. Nonetheless, seedlings from river sand produced highest number of leave (20.4), seedlings from topsoil produced highest plant height and largest leaf area of l0.62 cm and 37.l4 cm2 respectively. The seedlings from weathered sawdust produced the highest stem diameter of 0.79 mm, while seedlings from grinded coconut husk had lowest values for all the growth parameters measured. Therefore, it is recommended that river sand or weathered sawdust can be used to propagate Senna fistula seeds.


2017 ◽  
Vol 2 (1) ◽  
Author(s):  
Eric B. Kouam ◽  
Simon M. Ndo ◽  
Marie S. Mandou ◽  
Asafor H. Chotangui ◽  
Christopher M. Tankou

AbstractThis study was carried out to determine effects of salinity on germination and seedling development of commercially important common bean genotypes in Cameroon. The seeds of eight genotypes were used for both trials. The germination experiments were carried out on petri dishes in the laboratory while early growth trials continued in plastic pots in the screenhouse. Both stages were setup using a randomized complete block design with three replications. Germination and early growth trials of the different genotypes were studied using distilled water as control or osmotic potentials of 50, 100, 150 and 200mM NaCl to study the effects of salinity on germination and seedling growth characteristics. Leaf concentrations of Na+ and K+ were determined. At the germination level, germination percentage, germination index and the coefficient of velocity of germination decreased with increasing salinity while the mean germination time and time to 50% germination increased with increasing level of salt. All the growth variables decreased with increasing salinity with the exception of the root length which was not affected by salinity. It was observed that increasing salinity induced a significant increase in leaf Na+ and substantial reduction in the accumulation of K+ in the leaves. For ions accumulation, germination variables and growth parameters, significant differences at 0.001 probability levels were found among salinity treatments, common bean genotypes and most of their interactions. Significant correlations were found between all germination variables and between most growth parameters. From the effect of salt application, the common bean genotypes namely KEBCB049, KEB-CB053 and Mac-33 were the most tolerant while KEB-CB055 and KEB-CB050 were the most sensitive. The results confirm that there is genotypic variation in salinity tolerance and that the most tolerant genotypes should be further explored in selection programs, with the aim that they should be promoted for cultivation in tropical zones affected by salinity.


1988 ◽  
Vol 18 (7) ◽  
pp. 917-921 ◽  
Author(s):  
P. Chakravarty ◽  
L. Chatarpaul

We investigated the effects of Velpar L (hexazinone) on ectomycorrhizal (Laccarialaccata) and nonmycorrhizal Pinusresinosa seedlings in the greenhouse and in the field. In both greenhouse and field studies, seedling growth was reduced by Velpar L at 1, 2, and 4 kg/ha application rates in the short term (2 months' exposure) with significant recovery occurring afterwards. Seedling mortality occurred only with herbicide treatments and was higher in the greenhouse than in the field. The 4 kg/ha Velpar L treatment caused the highest mortality and toxicity was most pronounced in the mycorrhizal (Laccarialaccata inoculated) seedlings. In both experiments mycorrhizal infection was significantly reduced by 2 and 4 kg/ha Velpar L treatments during the 0- to 2-month and 2- to 6-month exposure periods, with significant recovery occurring in the latter. Although seedlings not infected with Laccarialaccata became mycorrhizal through unidentified indigenous species, their infection rates were also affected by Velpar L at all levels during the 0- to 2-month period and at the 2 and 4 kg/ha levels after 2–6 months of exposure to the herbicide.


Forests ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 740 ◽  
Author(s):  
Petra Veselá ◽  
Martina Vašutová ◽  
Karolína Hofmannová ◽  
Magda Edwards-Jonášová ◽  
Pavel Cudlín

Ectomycorrhizal (ECM) fungi importantly influence seedling growth, nutrition, and survival and create an extensive mycelial network interconnecting tree species and enabling resource redistribution. Due to their symbiotic relationship with trees, they are impacted by forest disturbances, which are of increasing relevance due to climate change. The effect of disturbance on seedling colonization and their morphology is still largely unknown. Seedling growth parameters and the ECM fungal assemblage on the roots of Norway spruce (Picea abies (L.) H. Karst.) seedlings were assessed in mature spruce forests attacked and destroyed by bark beetle and in a mature non-attacked forest as a reference. We did not detect significant differences in number of ECM species on seedling roots among forest types, but ECM species composition changed; Tylospora fibrillosa (Burt) Donk, Meliniomyces variabilis Hambl. & Sigler, and Phialocephala fortinii C.J.K. Wang & H.E. Wilcox were characteristic species in the forest destroyed by bark beetle, whereas Lactarius, Cortinarius, and Russula were in the mature forest. Forest type further significantly influenced the height, root length, and root collar thickness of seedlings and the proportion of exploration types of mycorrhizae.


1999 ◽  
Vol 13 (3) ◽  
pp. 530-535 ◽  
Author(s):  
Zhaohu Li ◽  
Robert H. Walker ◽  
Glenn Wehtje ◽  
H. Gary Hancock

Hypocotyl and root length reduction of soybean (Glycine max) seedlings when seeds were exposed to sulfentrazone during germination were used as indices to classify cultivar response to soil-applied sulfentrazone. Seeds of ‘Stonewall’ (sulfentrazone tolerant) and ‘Asgrow 6785’ (sulfentrazone sensitive) were imbibed and allowed to germinate in 0, 1, 5, 10, and 50 ppm aqueous sulfentrazone solutions for 4 d. Hypocotyl and root lengths were reduced in both cultivars, but the reductions were greater for Asgrow 6785 than for Stonewall. Subsequently, the relative sensitivity of 28 cultivars to sulfentrazone was independently determined by two variations of the hypocotyl reduction method (both conducted in the laboratory) and by traditional full-season field evaluation. Results from laboratory and field studies were in agreement for cultivars distinctly sensitive or tolerant to sulfentrazone. However, cultivars with intermediate tolerance in laboratory studies produced variable responses in the field.


2017 ◽  
Vol 4 (2) ◽  
pp. 316
Author(s):  
Nafi Sakila ◽  
Dinda Ayu Ramadhani ◽  
Ani Suryanti

Sei Nipah has enormous potential for natural resources. Natural resources that serve as the main livelihood in fulfilling daily needs in Kampung Nipah is shellfish. Shellfish (M. meretrix) is one of the shells that many interested by the surrounding community. The purpose of this research is to know growth parameter and age group of shellfish (M. meretrix) in Kampung Nipah. The sampling technique was done randomly (simple random sampling). Sampling time is done at low tide. Sampling was conducted in March - May 2017. The results showed differences in the length of different shells each month. The size group of shellfish (M. meretrix) found only one size group during the three months of the study. Analysis of shellfish growth parameters based on data of long frequency distribution showed length of infiniti (L?) 33,10 mm and growth growth (K) that was 1,21 per month. Von Bertalanffy Growth Parameters Lt = 33.1 (1-e [-1.21 (t + 0.12)]) Long infiniti size is seen the growth of shellfish shells can no longer be worked Shells reach maximum length at the age of 13 months with a shell length of 33.10 mm.The youthful shells have rapid growth and as age increases, when it reaches old age the rate of growth will slow even.


2020 ◽  
Vol 77 (3) ◽  
pp. 439-450 ◽  
Author(s):  
Andrea M.J. Perreault ◽  
Nan Zheng ◽  
Noel G. Cadigan

Response-selective stratified sampling (RSSS) has been well studied in the statistical literature; however, the application of the resulting statistical theories and methods to a specific case of RSSS in fisheries studies, namely length-stratified age sampling (LSAS), is inadequate. We review nine estimation approaches for RSSS found in the statistical and fisheries science literature in terms of three sampling components: the first phase length composition sample, the second phase age composition sample, and the sampling scheme. We compare the performance in terms of RRMSE (relative root mean squared error) for von Bertalanffy (vonB) growth model parameter estimation using an extensive simulation study. We further demonstrate methods by applying the two best-performing and the most popular methods to estimate the vonB model parameters for American plaice (Hippoglossoides platessoides) in NAFO Divisions 3LNO. Our simulations demonstrated that mis-specifying one or more of the three sampling components increases the RRMSEs, and this effect is magnified when the age distribution is incorrectly specified. The optimal approach for data based on LSAS is the empirical proportion approach, and we recommend this method for growth parameter estimation based on LSAS data.


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