Plant Phisiology

Pertumbuhan pohon dipengaruhi oleh lingkungan (edafis dan klimatis), pemuliaan genetik pohon, serta teknik silvikultur.  Dalam perkembangan selanjutnya, pohon tumbuh menjadi besar berkat perkembangan jaringan meristem primer apikal, akar dan meristem sekunder.  Akar sebagai bagian utama dari tumbuhan ternyata menjalankan fungsinya sebagai penopang dan penyedia zat hara dengan sangat menakjubkan.  Inilah yang disebut Jaringan Pengaman Unsur Hara

Laporan Praktikum  dengan dua judul, yaitu Absorbsi dan Transpirasi. Dengan tujuan untuk mengetahui pengaruh luas daun terhadap kecepatan absorbsi      air dan untuk mengetahui hubungan antara banyaknya stomata dengan kecepatan transpirasi.

Improving yield, biological efficiency (BE) and number of pinhead formation in Pleurotusflorida where achieved by nutritional supplement addition and use of casing overlay to substrate. In the present study utilization of soybean meal at two levels (2.5%- 5 % dry substrate weight) and Hogland solution (Hogland, ½ Hogland) without the use or with avail of casing overlay to substrate and with control substrate were evaluated. The results indicated that the addition of nutritional supplement and use of casing overlay to substrate had significant effect on yield and pinhead formation of oyster mushroom. Among the treatments, substrate received Hoagland solution (H, ½ H) without use of casing overlay had the lowest number of days to pinhead formation (20.5 days).
The maximum first yield (492.96 g/g) was observed in the use casing supplemented with 2.5% of soybean meal. Casing combined with ½ Hogland solution had the highest total yield (1121. 71 g/g), and biological efficiency (140.215). In general, It seems that application of Hogland solution for mushroom cultivation was very helpful to obtain high yield and high quality.  Get more articles at: http://www.innspub.net/volume-7-number-4-october-2015-ijaar/

PREMISE: Of all orchid species described, 70% live on phorophytes. Trees offer a vital space
with characteristics that influence the successful establishment and life cycle of orchids.
Field inventory and distribution analysis suggest that phorophyte selection is biased to
certain tree species that would serve as better hosts. Phorophyte bark is known as an
important factor that influences this preference, but the chemical and physical properties
of bark that contribute to creating a favorable space for orchids are still poorly understood.
In this work, the effect of bark physical characteristics on phorophyte preference of tropical
orchids was studied.
METHODS: Orchids and their phorophytes were counted and identified along transects
inside two natural reserves in Southeast Mexico. A rhytidome classification was used to
describe the bark decoration patterns of the phorophytes. To quantify bark fissuring,
we developed a new protocol based on image processing of light micrographs using
free-access software. Bark topology characterization was complemented with scanning
electronic microscopy. Maximum and minimum water content was also determined.
RESULTS: Analyses of bark decorations and bark fissuring were not enough to explain the
preference found for some tropical trees. In contrast, a positive relationship was found
among water-storage capacity, bark porosity, and phorophyte preference. The host trees
preferred by most orchids have bark with higher pore density and higher water retention
after draining.
CONCLUSIONS: Unexpectedly, the phorophytes preferred by orchids are not those with
more fissured bark but those with a higher ability to retain minimum water content after
draining, which is a bark property positively correlated with higher pore density. Our data
indicate that the bark microenvironment, determined by topology and water storage
capacity, has a pivotal role in phorophyte specificity, a key factor that affects orchid
diversity and distribution in the world.

Walaupun produksi beras setiap tahun bertambah tetapi masih belum mencukupi kebutuhan para konsumen, khususnya di Indonesia. Pemerintah Indonesia berupaya meningkatkan produksi padi dengan memanfaatkan lahan yang sudah berubah fungsi tetapi masih bias digunakan untuk menanam padi, seperti lahan sawah yang beralih fungsi menjadi kebun sawit. Desain Penelitian ini adalah RPT (Rancangan Petak Terbagi), dimana Petak Utama (PU) adalah varietas (IR64 & Ciherang), sedangkan Anak Petak (AP) yaitu saat pemberian PBZ (sebelum 7 hari,  saat Inisiasi Malai dan 7 hari setelah inisiasi malai (IM)) serta 5 ulangan. larutan PBZ yang diberikan yaitu 400 mg/L dan dosis yang diberikan dengan standar merata kesemua permukaan daun. Pemberian pupuk yaitu, Phospat (TSP) dan Kalium (KCl) diberikan sebagai pupuk dasar, dan 3 kali pemberian untuk N (Urea). Organisme Pengganggu Tanaman (OPM), dan gulma dikelola dengan pemakaian racun kimia jika sudah mencapai ambang batas ekonomi. Parameter yang diamati adalah luas daun, tinggi tanaman dan diameter batang. Hasil riset menunjukkan bahwa tinggi tanaman yang paling rendah yaitu saat aplikasi seminggu sebelum IM, sedangkan diameter batang yang terbesar diperoleh pada pemberian tujuh hari sebelum IM juga, begitu juga dengan luas daun, dimana daun bendera yang terluas ditemukan pada aplikasi 7 hari setelah IM. Untuk ketiga parameter, tidak dijumpai interkasi antara perlakuan waktu aplikasi PBZ dengan varietas yang diuji. Kesimpulannya, dari 3 waktu aplikasi PBZ dapat dilihat bahwa pemberian yang terbaik adalah  tujuh hari sebelum IM.

Salinity, of both soil and water, is one of the main causes of crop yield decline. Within this context, the objective of this study was to evaluate the influence of different salts on the germination of chia seeds. The experiment was conducted in a BOD chamber at a constant temperature of 20 °C and in the presence of light. The seeds were placed on paper soaked with aqueous solutions of calcium chloride (CaCl 2), sodium chloride (NaCl), potassium chloride (KCl), and magnesium chloride (MgCl 2), at the osmotic potentials zero,-0.10,-0.20,-0.30, and-0.40 MPa. The effect of the salinity was evaluated using a germination test, with counts on days 7 and 14 after sowing. Based on the results, chia seeds tolerate concentrations of NaCl to-0.4 MPa and KCl to-0.20 MPa. The salts CaCl 2 and MgCl 2 had a negative effect on the germination and vigor of the chia seeds for the osmotic potentials-0.30 MPa and-0.20 MPa, respectively. Germinação de sementes de chia submetidas ao estresse salino Resumo A salinidade, tanto dos solos como das águas, é uma das principais causas da queda de rendimento das culturas. Neste contexto, o objetivo deste estudo foi avaliar a influência de diferentes sais na germinação de sementes de chia. O experimento foi conduzido em câmara BOD, na temperatura constante de 20 °C e em presença de luz. As sementes foram colocadas sobre papel embebido em soluções aquosas de cloreto de cálcio (CaCl 2), cloreto de sódio (NaCl), cloreto de potássio (KCl) e cloreto de magnésio (MgCl 2) nos potenciais osmóticos correspondentes a zero;-0,10;-0,20;-0,30 e-0,40 MPa. O efeito da salinidade foi avaliado através do teste de germinação com contagens aos 7 dias e 14 dias após a semeadura. De acordo com os resultados é possível concluir que as sementes de chia toleram concentrações de NaCl até-0,4 MPa e KCl até-0,20 MPa. Os sais CaCl 2 e MgCl 2 apresentam efeito negativo sobre a germinação e o vigor das sementes de chia a partir dos potenciais osmóticos de-0,30 MPa e-0,20 MPa, respectivamente. Palavras-chave: Salvia hispanica, salinidade, água.

A study was made to evaluate the effect of a castor oil-based detergent on strawberry crops treated with different classes of pesticides,
namely deltamethrin, folpet, tebuconazole, abamectin and mancozeb, in a controlled environment. Experimental crops of greenhouse
strawberries were cultivated in five different ways with control groups using pesticides and castor oil-based detergent. The results
showed that the group 2, which was treated with castor oil-based detergent, presented the lowest amount of pesticide residues and
the highest quality of fruit produced.

In this paper, the need of increasing transdisciplinarity research is advocated. After having set out some peculiarity of transdisciplinarity compared with related concepts such as multidisciplinarity and interdisciplinarity, four evolutionary stages of scientific disciplines, based on a model recently proposed (Shneider in Trends Biochem Sci 34:217–223, 2009) are presented. This model is then applied to the case of Plant Physiology in order to attempt an evaluation of the potential for transdisciplinary engagement of the discipline, and each of the four stages of the discipline is evaluated. In conclusion, some future perspectives of Plant Physiology are sketched with reference to its transdisciplinary potential.

The strawberry market in Cundinamarca (Colombia)
is mainly size driven with no consideration for its
maturation state and nutritional quality, wasting
therefore, its organoleptic and nutritional potential.
For that reason, the physicochemical differences
among seven strawberry varieties (Albión, Dulce
Ana, Lucía, Monterrey, Ruby June, Sabrina and
Ventana) cultivated in the municipality of Sibaté
(Cundinamarca) were established. Fruits collected
from a productive plot with homogeneous cultivation
management conditions were analyzed in six
maturity states, establishing the degree of red
pigmentation according to the Colombian Standard
ntc 4103. Fresh weight, size, color, firmness, total
soluble solids (tss), total titratable acidity (tta),
maturity and respiration indices were evaluated.
Fruits in stages 4, 2 and 3 developed their largest
size and weight, where the variety Dulce Ana stands
out. The highest color index values were found in the
maturity stage 5 in the variety Ventana. Moreover,
the highest firmness values were recorded in stages
4 and 5 in the varieties Monterrey and Ventana.
The varieties Sabrina, Dulce Ana and Monterrey
accumulated the highest tss concentration and
the last two showed the best maturity relations.
Respiration rates increased with maturation,
especially from stage 3. The results suggest that
the optimum commercialization and consumption
points are stages 3 and 4, namely because these
stages exhibit the highest maturity index and fruit
weight. Among the varieties studied, Monterrey
stands out due to its firmness and maturity index.

Sweet potato is a crop with a wide capacity to adapt to adverse conditions. To study the tolerance of the sweet potato to a low-altitude environment, 34 genotypes comprising three groups from different altitude conditions ranging from 18-599, 924-1298, 1401-2555 meters above sea level were evaluated. These genotypes were evaluated through ecophysiological parameters: net photosintetic rate (Pn), stomatal conductance (G S), transpiration (E), leaf internal CO 2 (ICO 2), vapor pressure deficit (VPD) and leaf internal temperate (LT). sSubsequently, water use efficiency (WUE) and carboxylation efficiency index (CEI) were estimated. Simultaneously, morpho-agronomic characterization of the genotypes was conducted including descriptors and morpho-colorimetric parameters. A wide ecophysiological variability was found among genotypes from high, intermediate and low altitudes, when those were evaluated under low altitude conditions. The genotypes that presented major soil coverage efficiency and leaf size showed greater Pn, WUE and CEI, and Low VPD and E, aspects that benefited the ability to form roots the under low-altitude environment. The altitudinal origin of the genotypes influenced the ecophysiological response under low altitude conditions. The capacity of certain sweet potato genotypes to tolerate low altitude conditions were due to to different mechanisms, such as certain morphoagronomic traits that allowed them to adjust their physiological processes, especially those related to photosynthesis.

The objectives of this experiment were to study (a) response of maize genotypes
drought stress during anthesis up to grain filling or maturity stages and (b)
determine characters as drought tolerance indicators. Factorial randomize complete
block design this experiment was used with two factors. The first factor was drought
tolerance and sensitive genotypes and the second factor was periods of drought
stress consisted of three condition: (i) drought at anthesis up to grain filling stages,
(ii) drought at anthesis up to maturity stages, and (iii) optimum condition. The
results of research showed that tolerance genotypes had the abilities to maintain
shoot growth (plant height and shoot dry weight) and suppress leaf damage under
drought condition. The abilities of drought tolerant were supported by heavy root dry
weight while resulted the extend of root absorbing more water. The ability of maize
genotypes in keeping shoot growth, suppressing transpiration due to lower leaf
stomata density and higher water use efficiency is an important factors in
suppressing yield loss in drought condition. The sensitive genotypes was not had
these abilities since it had low root dry weight, therefore, the root extension was not
supported for absorbing adequate amount of water for shoot growth (shoot dry
weight and plant height) and increasing the intensity of damage leaf under drought
condition was high. Besides, the sensitive genotype had higher leaf stomata density
and lower level of water use efficiency which caused the increasing yield decrease
(grain wieght/plant) compare to tolerance genotypes, more over, in longer drought
period of theirs genotypes were not filled.