Wheat Developmental Traits as Affected by the Interaction between Eps-7D and Temperature under Contrasting Photoperiods with Insensitive Ppd-D1 Background

Earliness per se (Eps) genes are important to fine tune adaptation, and studying their probable pleiotropic effect on wheat yield traits is worthwhile. In addition, it has been shown that some Eps genes interact with temperature and therefore determining the likely Eps × temperature interaction is needed for each newly identified Eps gene. We studied two NILs differing in the newly identified Eps-7D (carrying insensitive Ppd-D1 in the background) under three temperature regimes (9, 15 and 18 °C) and two photoperiods (12 and 24 h). Eps-7D affected time to anthesis as expected and the Eps-7D-late allele extended both the period before and after terminal spikelet. The interaction effect of Eps-7D × temperature was significant but not cross-over: the magnitude and level of significance of the difference between NILs with the late or early allele was affected by the growing temperature (i.e., difference was least at 18 °C and largest at 9 °C), and the differences caused due to temperature sensitivity were influenced by photoperiod. The rate of leaf initiation was faster in NIL with Eps-7D-early than with the late allele which compensated for the shorter duration of leaf initiation resulting in similar final leaf number between two NILs. Eps-7D-late consistently increased spike fertility through improving floret primordia survival as a consequence of extending the late reproductive phase.

Wheat developmental traits as affected by the interaction between Eps-7D and temperature under contrasting photoperiods with insensitive Ppd-D1 background

Earliness per se (Eps) genes are important to fine tune adaptation, and studying their probable pleiotropic effect on wheat yield traits is worthwhile. In addition, it has been shown that some Eps genes interact with temperature. We studied two NILs differing in the newly identified Eps-7D but carrying insensitive Ppd-D1 in the background under three temperature regimes (9, 15 and 18 °C) and two photoperiods (12 h and 24 h). Eps-7D affected time to anthesis as expected and the Eps-7D-late allele extended both the period before and after terminal spikelet. The interaction effect of Eps-7D × temperature was significant but not cross-over: the magnitude and level of significance of the difference between NILs with the late or early allele was affected by the growing temperature (i.e. difference was least at 18 °C and largest at 9 °C), and differences in temperature sensitivity was influenced by photoperiod. Rate of leaf initiation was faster in NIL with Eps-7D-early than with the late allele which compensated for the shorter duration of leaf initiation resulting in similar final leaf number between two NILs. Eps-7D-late consistently increased spike fertility through improving floret primordia survival as a consequence of extending the late reproductive phase.

Molecular and Hormonal Regulation of Leaf Morphogenesis in Arabidopsis

Shoot apical meristems (SAM) are tissues that function as a site of continuous organogenesis, which indicates that a small pool of pluripotent stem cells replenishes into lateral organs. The coordination of intercellular and intracellular networks is essential for maintaining SAM structure and size and also leads to patterning and formation of lateral organs. Leaves initiate from the flanks of SAM and then develop into a flattened structure with variable sizes and forms. This process is mainly regulated by the transcriptional regulators and mechanical properties that modulate leaf development. Leaf initiation along with proper orientation is necessary for photosynthesis and thus vital for plant survival. Leaf development is controlled by different components such as hormones, transcription factors, miRNAs, small peptides, and epigenetic marks. Moreover, the adaxial/abaxial cell fate, lamina growth, and shape of margins are determined by certain regulatory mechanisms. The over-expression and repression of various factors responsible for leaf initiation, development, and shape have been previously studied in several mutants. However, in this review, we collectively discuss how these factors modulate leaf development in the context of leaf initiation, polarity establishment, leaf flattening and shape.

DETECTION OF ADHESION-FREE AREAS AND EXFOLIATIONS IN MULTILAYER STRUCTURES BY THE ACOUSTIC-TOPOGRAPHIC METHOD

Physical the bases of acoustic-topographic method of defektoskopiya of multilayer structures are briefly covered. Installation for implementation of acoustic-topographic method in two options is developed and mounted: with the magnetostrictive activator and with the electromagnetic (shock) activator. By pilot studies it is established that at control by acoustic-topographic method of brazed and welded structures sensitivity of control significantly (in 2–3 times) is higher, than at control by other methods of defektoskopiya. It is established also that the zone of control of multilayer glued structures is much less, than at control of brazed and welded structures. It is shown that the greatest thickness of the upper leaf of structure at which control by acoustic-topographic method with sufficient sensitivity is still possible, is equal to about 1 mm, at control of structures with thickness of the upper leaf initiation of elastic oscillations it is reasonable to carry out over 1 mm in the shock way. Repeated control with change of point of input of ultrasonic oscillations is in certain cases necessary for specification of picture of distribution of powder near initial point of input of oscillations.

Impact of Initial Environmental Conditions on Germination, Growth, and Development of Cucumis Sativus at Lamjung

Cucumber is the fourth most important vegetable crop worldwide favored for its edible fruit. Cucumber cannot be grown in the winter months due to its intolerance to cold and frost. An experiment was conducted in IAAS, Lamjung to test the effectiveness of various nursery raising conditions for achieving earlier harvest in spring. Three treatments viz. cold frame, hotbed, and open were selected and replicated 30 times each. Data on germination speed, germination percentage, true leaf initiation, plant height, tendril initiation, days to first flowering, days to harvesting, length and diameter of fruit and fruit yield were recorded. Hotbed achieved earlier germination (8 days) followed by cold frames (8.57 days) and open (12.73 days) respectively with cold frame having the highest germination percentage (98%) followed by a hotbed (96%) and open (90%). True leaf initiation was earlier in a cold frame (21.5 days), followed by hot bed (22.83 days) and open (30.97 days). Transplanting of cold frame and hotbed seedlings could be performed 10 days prior to open. Final height attained was significantly maximum for cold-frame plants (97.93 cm) and minimum for a hotbed (76.19 cm) with open being indifferent (86.17 cm) to cold frame and hotbed. Days to tendril initiation, days to flowering and days to first harvest were 57.52, 66.87 and 82.93 days respectively for cold-frame which was significantly minimum compared to hotbed (64.04, 70.38 and 86.95 days) and open (65.73, 71.23, 85.58 days), both being indifferent. Significantly maximum yield was obtained from cold-frame (1465.73 g) with open yielding significantly minimum (1004.06 g) and hotbed being indifferent (1122.45 g) to cold frame and open. Cold-frames are found to be comparatively effective to hotbed and open condition with 3.12 days earlier and 35% higher yield.

Vegetative and reproductive phenology of Aquilaria malaccensis Lam. (Agarwood) in Cachar District, Assam, India

Aquilaria malaccensis Lam., a threatened tree commonly called agarwood, is emerging as one of the most promising commercially important aromatic species in the world. This paper presents the findings on the vegetative and reproductive phenology of Aquilaria malaccensis from the secondary tropical evergreen forest in Cachar district, Assam. The effect of tree phenology and the influence of seasonal drought and environmental variables, especially temperature and precipitation, on various phenophases such as leaf initiation, leaf-fall, flowering, and fruiting were investigated. For this, a quantitative assessment was made at 15-day intervals by tagging 35 trees over a period of two years. Seasonal influence on the phenology of different phenophases was correlated with environmental variables and Spearman’s rank correlation coefficient was employed. Leaf initiation was positively correlated with temperature (rs=0.694, p=<0.05), while leaf-fall was negatively correlated with temperature (rs=-0.542, p=<0.05) and rainfall (rs=-0.521, p=<0.05). Flowering (rs=0.713, p=<0.01; rs=0.713, p=<0.01) and fruiting (rs=0.721, p=<0.01; rs=0.775, p=<0.01) were positively and significantly influenced by temperature and rainfall. The study suggests that temperature and rainfall were major determinants of the vegetative and reproductive phenology of A. malaccensis, and any changes in these variables under expected climate change phenomenon may have a profound effect on phenophases of this threatened tree species.