Submergence

The recent advancements in rice genomics offer a lot of promise for developing new varieties. The rapid advances made in plant physiology and biochemistry, molecular genetics, and structural and functional genomics demonstrated the ability to identify complex mechanisms of desirable traits and use them to develop rice breeding products combining multiple abiotic stress tolerances. These developments facilitated the development and use of faster approaches and breeding strategies for germplasm improvement. Remarkable achievements can be demonstrated for submergence tolerance. The discovery and cloning of the SUB1A gene facilitated the introgression of the gene to several high yielding varieties that have now been released in South and South-East Asian countries. Moreover, considerable progress was made in mapping the major QTL such as SalTol thus providing opportunities to fast track the introgression of SalTol QTL to popular varieties in Bangladesh, India, Vietnam and Philippines. Drought tolerance QTLs are identified through a combination of genomics and selection approaches. The fined mapped QTLs controlling tolerance to abiotic stresses (e.g. drought, salinity, P deficiency, and submergence) can be the first tier of traits for marker-assisted selection (MAS) thus will provide greater opportunity to reduce the highrisk rice production in the rainfed lowland areas. The issue of climate change compels breeders to combine multiple abiotic traits into a single genotype (salinity and submergence, submergence and drought, salinity and drought, and salinity-submergence-drought) because these traits co-exist in one cropping season. With the advent of recent biotechnological tools, knowledge of the genetic mechanisms and newer sources of tolerance, rice scientists can explore radical approaches to design the next generation of rice varieties that are climate-change-resilient and acceptable to the farmers. The challenge still is to make these biotechnological tools convenient to plant breeders for them to execute precision breeding.

Jerusalem aritichoke (Helianthus tuberosus) is an Angiosperm plant species of the Compositae family, and a C-3 warm-season species of sunflower. This herbaceous plant shows significant ecological and commercial importance for its strong stress tolerance, very high yield potential and more application areas such as chemicals, pharmaceuticals and industrial applications. The morphologic, bio-ecological characteristics, the utilization and applied values of H.

Single nucleotide polymorphisms and restriction digestion-based haplotype variations among 160 flood prone rice varieties were analyzed with enzymes Alu I and Cac8 I to generate polymorphisms at Sub1A and Sub1C loci (conferring submergence tolerance), respectively. Haplotype associated with phenotype was used to study the haplotype variations at Sub1A and Sub1C loci and to determine their functional influence on submergence tolerance and stem elongation. Three patterns at Sub1A locus, Sub1A0 (null allele), Sub1A1 (does not cut) and Sub1A2 (one SNP), and four patterns at Sub1C locus, Sub1C1, Sub1C2, Sub1C3 and Sub1C4, were generated. Both tolerant Sub1A1 and intolerant Sub1A2 had the same length, but the difference was presence of a restriction site in the Sub1A2, but absent at the Sub1A1. Further, two types of polymorphism were detected at the Sub1C, one included major length polymorphisms (165, 170 and 175 bp) and the other was a single restriction site at different position. Eight haplotypes (different combinations of the two loci), A1C1, A1C2, A1C4, A2C2, A2C4, A0C2, A0C3 and A0C4, were detected among 160 varieties. Haplotype A1C1 was comparatively more related to haplotypes A1C2 and A1C4, having the same Sub1A allele, and these haplotypes were found only in Bangladeshi, Sri Lankan and Indian varieties. Most tolerant varieties in A1C1 haplotype showed slow elongation, having tolerant specific Sub1A1 and Sub1C1 alleles. Further, the varieties Madabaru and Kottamali (A2C2) also showed moderate level of tolerance without Sub1A1 allele. These varieties were different with FR13A and also suspected to carry different novel tolerant genes at other loci. These materials could be used for hybridization with Sub1 varieties for pyramiding additional tolerant specific alleles into a single genotype for improving submergence tolerance in rice.

Climate change natural – Impact on water resources in Himalaya
Ritesh Arya,                                 aryadrillers@gmail.com, www.aryadriler.com

Abstract:

“God give me the courage to change the things I can (pollution and technology), accept the things I cannot change (climate change) ,serenity and wisdom to know the difference” Dr Ritesh Arya .

Present paper is based on discovery of paleoclimatic signatures made by Indus glacier/river on the granites of Ladakh batholiths on the banks of river Indus since 11714 years.  Author discovered these signatures while exploring, drilling and developing groundwater on the borders of China(Changthang)  and Pakistan(Siachen, Kargil) in NW Indian Himalaya for Army and civil population for the last 12 years.
These signatures resembles alphabet C, hence named Aryas C cycles. Cyclicity of cooling, warming and again cooling can be very well understood by writing alphabet C. The starting point of alphabet C represents the cooling phase (ICE age) and as we continue to draw the curve there is gradual curvilinear transformation from cooling maxima to warming phase. Half of the C curve represents the warming maxima (an event marked by flooding, cyclones, sea level rise, desertification, biodiversity explosion, increase in GHGs) and completion of alphabet C represents the culmination of the gradual curvilinear transformation from warming to cooling coinciding with ICE age (marked by squeezing and freezing of water resources, glaciations, desertification, competition, mass extinctions, decrease in GHGs). Transferring this sentence geologically means that since there is less water in the system during ICE age so there is less erosion hence we get starting and end of C cycle but as the temperature increases the rate of erosion increases hence the curvilinear depressions are created making the upper half of the warming cycling, center of alphabet C is marked by warming maxima. Then there is again gradual transformation from warming to cooling and as the water in the system decreases there is less erosion therefore we get a geomorphological feature which resembles the lower half of alphabet C finally ending into the ICE age.  So uniformity in the paleoclimatic signatures discovered in Ladakh Himalaya which resembles alphabet C , for the first time geologically and scientifically explains cooling, warming and again cooling phase in nature to be a natural climate cyclic process.
Granites played important role in the preservation of these climatic signatures because they are very hard and compact as compared to other rocks found in the Himalayas which are fragile and susceptible to faster rate of weathering and erosion making preservation of the signatures tedious task. Taphonomical analysis of these C curves in massive Granites show great role of lithology and geomorphology in preservation and understanding the cyclicity of these climate signatures which have been beautifully preserved in the Ladakh Batholith in NW Himalaya.  Author observed 10 such cycles in the site,8 complete and 2 half cycle. Geomathematical modeling of these paleoclimatic signatures show that after every 4 cycles there is a half cycle. According to this model each complete C cycle is of 1338.6 years and half C cycle is 669.3 years.
Based on this model author has tried to correlate the paleo climatic and geological events in the past and found that lot of events can be explained by Aryas C cycles.  Important question now is which part of the C cycle are we now. Seeing the paleoclimatic signature in the Batholiths of Ladakh we are presently in the warming maxima times and are curvilinearly moving into the cooling phase finally culminating into ICE age in 2344 years, represented by the lower part of alphabet C. So enjoy global warming by building sustainable habitats in geologically favorable locations because the next warming maxima will be in 3014.
Author also tries to relate circumstantial evidences with the dates of warming and cooling proposed in this model which  coincides with the same.

L.) cultivars namely FR13A (tolerant to submergence), IR42 (susceptible to submergence) and Sabita (adapted to medium depth, 0-50 cm stagnant flooding), varying degrees of tolerance to submergence under control and 8 days after submergence conditions. During submergence, Sabita and IR 42 accelerated the rate of stem and leaf elongation more than that of FR 13A. Submergence significantly reduces the cellulose and hemicelluloses content. The decrease was more pronounced in susceptible rice cultivar than that of tolerant rice cultivar. Lignifications’ was monitored by measuring the content of lignin and the activities of two enzymes of the lignin biosynthetic pathway, coniferyl alcohol dehydrogenase (CAD) and phenylalanine ammonia-lyase (PAL) in rice shoots. Lignin content and PAL and CAD activity was more in susceptible cv. both under control and 8d after submergence. In conclusion submergence induced elongation of rice shoot might decreased the structural carbohydrate level as our ex...

Rice submergence is the condition by which the water level rises above the rice crop canopy. In general, rice plant response to submergence is to elongate its shoots above the rising water level. This costs in energy and eventually has a direct impact in terms of reducing yields. A specific gene, called Sub1, when introgressed into popular rice varieties by Marker Assisted Back-crossing, nearly stops the natural elongation process and permits a given local rice variety to sustain submerged conditions for a generally recognized period of about 2 weeks. Plant breeders now look for well-identified and location-accurate submergence areas in order to disseminate such improved local rice varieties. Remote sensing is proposed to provide surface water maps at high temporal resolution, determining a percentage of occurrences of surface water for a given pixel. Occurrence is defined as the count of days of identified surface water within a given period, returned in a percentage on that period. Rice area maps and knowledge of crop calendars are proposed to add to the assessment of submergence prone areas in the Northeastern Thailand.

Nonlinear weirs are among the hydraulic structures that, despite their great importance and application, so far, no general method for estimating their discharge capacity has been accomplished. Laboratory or numerical modelling is commonly used to achieve nonlinear weir discharge capacity. It should be noted that employing the design equation from one geometric family of nonlinear weirs to another is impractical. The utilization of numerical or laboratory models in the preliminary stages of the design of these structures is a time and cost-consuming process, which is highlighted by the variety of nonlinear weir geometry. In this research, a general method for estimating the nonlinear weirs discharge capacity is presented. The proposed method analyzes nonlinear weir discharge capacity using energy and discharge equations for discretized solution fields. Furthermore, the local submergence in nonlinear weirs, which has a tangible effect on their discharge capacity, has been corrected. Results of laboratory models performed on the oblique weir, arced labyrinth weir, and Isabella dam weir have been used to evaluate the efficiency of the proposed method. The proposed method with high correlation and accuracy has estimated the discharge capacity of these weirs. The maximum error observed was 12 percent for the oblique weir,15 percent for the arced labyrinth weir, and 15 percent for the Isabella Dam weir.

This discussion focuses on data acquisition strategies for spatially-averaged mean velocities over rough surface flow and the elevation of the zero-velocity plane (or zero-plane displacement) which is an important parameter in logarithmic velocity profiles for rough bed flow problems. It is demonstrated that the compound effects of relative submergence and zero-plane displacement should be accounted for to quantify the behaviour of surface roughness.