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During the domestication process, farmers influence the reproduction and care of organisms to ensure a predictable supply of the resource of interest, causing changes in phenotypic and genotypic character frequencies. In Chile, as a result of unconscious selection and domestication process, farmed populations of the red alga Agarophyton chilensis have most likely undergone a reduction in genetic diversity and a modification in life-history traits compared to wild populations. In order to understand the implications that these processes may have in A. chilensis, we investigated how temperature variations (10 °C, 15 °C, and 20 °C) affect growth and photosynthetic responses of natural and farmed populations from three different localities along the Chilean coast. Natural population’s growth decreased at low and high temperature levels while all three farmed populations respond in a very similar way to temperature variation. We propose that a possible outcome of farming, in the A. chilensis, vegetatively propagated crops, could have been the selection of general-purpose-genotypes able to perform adequately across the range of temperature tested in our experiment. Furthermore, our results showed that photosynthetic activity was also affected by temperature treatments (e.g., different maximum maximal electron transport rate and quantum yield values depending on the population type and temperature). In a context of climate change, A. chilensis farmed populations may be better able to cope with impacts of anthropogenic activities than natural populations due to the buffer effect of their general-purpose-genotypes, tolerant to a wide range of conditions

In this study, a brown macroalgae species, Saccharina latissima, processed to increase its protein concentration, and a red macroalgae species, Porphyra spp., were used to evaluate their in vivo digestibility, rumen fermentation and blood amino acid concentrations. Four castrated rams were used, whose diets were supplemented with a protein-rich fraction of S. latissima, a commercial Porphyra spp. and soybean meal (SBM). Our results show that the protein digestibility of a diet with S. latissima extract was lower (0.55) than those with Porphyra spp. (0.64) and SBM (0.66). In spite of the higher nitrogen (N) intake of diets containing Porphyra spp. and SBM (20.9 and 19.8 g N/day, respectively) than that with S. latissima (18.6 g N/day), the ratio of N excreted in faeces to total N intake was significantly higher in the diet with S. latissima than those with Porphyra spp. and SBM. This reflects that the utilization of protein in S. latissima was impaired, possibly due to reduced microbial activity. The latter statement is corroborated by lower volatile fatty acid composition (25.6, 54.8 and 100 mmol/l for S. latissima, Porphyra spp. and SBM, respectively) and a non-significant tendency for lower ammonia concentration observed in diets with 

S. latissima and Porphyra spp. compared to SBM. It is important to note that the S. latissima used in this trial was rinsed during processing to remove salt. This process potentially also removes other water-soluble compounds, such as free amino acids, and may have increased the relative fraction of protein resistant to rumen degradation and intestinal absorption. Furthermore, the phlorotannins present in macroalgae may have formed complexes with protein and fibre, further limiting their degradability in rumen and absorption in small intestines. We recommend that further studies explore the extent to which processing of macroalgae affects its nutritive properties and rumen degradability, in addition to studies to measure the intestinal absorption of these macroalgae species. 

The study was carried out in a private nursery in Al-Qasim district located in Babil governorate in the period from 1/9/2018 to 1/9/2019 to study the effect of spraying with marine algae extract (Agazone) and cytokinin spray (CPPU) on the growth of local sour lemon grafted on the origin of Citrus aurantium. The experiment was carried out according to the design of the complete random sectors and three replicates, where the experiment included spraying four concentrations of seaweed extract (Agazone) 0, 3, 6, 9ml /L-1 and four levels of spray regulator growth (CPPU) 0,2,4,8 mg/L-1. The results showed a significant effect in all the studied traits, especially the treatment of spraying with Agazone algae extract at the concentration of 9 mL/-1 and spraying with growth regulator CPPU at the concentration of 8 mg/ L-1 as it achieved a significant increase in seedling height, number of leaves, area of leaves, increase plant stem diameter rate. The stem was 78.75 cm, 83.42 cm, 63.83 leaves. Seedlings-1, 65.33 leaves. Seedlings-1, 1401.25 creamy 2. Seedlings-1, 1633.56 creamy 2. Seedlings-1, 1.65 mm, 1.44 mm as well as leaf content of chlorophyll and nitrogen were 47.89 SPAD, 47.98 SPAD, 2.47%, 2.44% respectively for both study factors. 

The effect of repeated harvesting on the growth of Gelidiella acerosa was studied for one year from August '87 to July '88 and Gracilaria corticata var. corticata for two years from July '87 to May '89. The growth of these agar yielding seaweeds depended on the harvesting season and the interval between successive harvests. The regrowth of these red algae continues as long as the basal rhizomatous portion is intact with the substratum. Hence harvest should be done by pruning the plants leaving the basal portions instead of plucking the whole plants. The commercial exploitation of G. acerosa should be made only during April to July and G. corticata var. corticata during April to June and September to November giving ample interval for their regrowth to harvestable size.