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Among various abiotic stresses, water is reported as a rare entity in many parts of the world. Decreased frequency of precipitation and global temperature rise will further aggravate the situation in future. Being C4 plant, sugarcane requires generous water for the proper growth. Plant root system primarily supports above-ground growth by anchoring in the soil and facilitates water and nutrients uptake from the soil. The plasticity and dynamic nature of roots endow plants for the uptake of vital nutrients from the soil even under soil moisture conditions. In sugarcane, the major part of root system are generally observed in the upper soil layers, while limited water availability shifts the root growth towards the lower soil layer to sustained water uptake. In addition, root traits are directly related to physiological traits of the shoot to cope up with water limited situations via reduction in stomatal conductance and an upsurge in density and deep root traits, adaptations at biochemical and molecular level which includes osmotic adjustment and ROS detoxification. Under stressed conditions, these complex interactive systems adjust homeo-statically to minimize the adverse impacts of stress and sustain balanced metabolism. Therefore, the present chapter deals with physiological and biochemical traits along with root traits that helps for better productivity of sugarcane under water-limited conditions.

A field experiment was conducted during spring season of 2014–15 and 2015–16 at CCS HAU, RRS, Karnal to evaluate the response of four sugarcane (Saccharum officinarum L.) varieties differing in their maturity i.e. CoS 767 (Mid late), CoH128 (Mid late), CoJ 64 (Early) and Co 0238 (Early) to deficit irrigation. The experiment was conducted in split plot design with three replications. Based on available soil moisture (ASM), three treatments i.e. irrigation at 50% ASM (control), 40% ASM (mild stress) and 30% ASM (severe stress) were imposed in main plot and sugarcane varieties in sub-plot. Under deficit irrigation, leaf area, leaf area index (LAI), crop grown rate (CGR), relative growth rate (RGR) and net assimilation rate (NAR), significantly, reduced at 30–60 and 60–90 DAP in all the varieties and the varieties Co 0238 and CoS 767 showed least reduction. The yield parameters, viz. number of millable canes, cane length, internodal length and single cane weight reduced significantly under water limited conditions and proved to be the most sensitive yield components responsible for decrease in cane and sugar yield. Cane yield and sugar yield reduced by 36.18% and 40.47%, and 27.5% and 31.09% at 30% and 40% ASM level, respectively. Co 0238 produced highest average cane yield and sugar yield (83.05 and 10.17 t/ha) followed by CoS 767 (68.23 and 8.28 t/ ha). Moreover, after stress revival Co 0238 and CoS 767 were able to recover faster which qualified these varieties to face short periods of drought without major losses in the initial phase of development.

Globally, wheat is a major staple food crop that provides 20% of food calories for 30% of the human population. Wheat growth and production are significantly affected by salt stress at various stages and adversely affect germination, vegetative growth, stomatal conductance, photosynthesis, reproductive behavior, protein synthesis, enzymatic activity and finally hampered grain yield. Maintenance of low Na+/K+ ratio, antioxidants and hormonal regulation, and accumulation of compatible osmolytes such as glycine betaine, proline and trehalose help the wheat genotypes to mitigate the negative effects of salt stress. Recent studies have reported various mechanisms at the physiological, biochemical and molecular levels to adapt the salinity stress in various ecologies. Salt tolerant genotypes can be developed by conventional breeding approaches and through biotechnological approaches. This chapter reviews the updates on mechanisms and recent approaches to structure the salt-tolerant and high-yielding genotypes.

This investigation aimed to optimize the time, pH, pressure, and temperature of sugarcane juice pasteurization and to develop a “ready to serve” bottled sugarcane juice with a high preservation efficiency. Fresh sugarcane juice was extracted from sugarcane genotype Co 89003, and beverage samples were collected using three different treatments: sulphitation of juice with the addition of potassium metabisulphite (KMS-25, 50, 100, and 150 ppm), acidification of juice (addition of citric acid, to reduce the pH of the juice to 4.8, 4.5, and 4.25), and steam treatment of the canes (5 min, 10, and 15 min at 7 psi). In all treatments, the juice was pasteurized in glass bottles @ 65 °C for 25 min and stored at low temperature (5 °C) in pre-sterilized glass bottles. Juice properties such as the ˚Brix, total sugar, pH, and total phenolic content decreased with storage, whereas the microbial count, titrable acidity, and reducing sugar content significantly increased during storage. The addition of KMS, citric acid, and the steam treatment reduced the browning of juice and maintained the color of juice during storage, by inhibiting the polyphenol oxidase enzyme activity, from 0.571 unit/mL to 0.1 unit/mL. Among the selected treatments, sugarcane juice with KMS (100 and 150 ppm) and steam treatment of the canes for 5 and 10 min at 7 psi showed the minimum changes in physico-chemical properties, sensory qualities, and restricted microbial growth. Thesulphitation treatment with pasteurization proved best for increasing the shelf life of sugarcane juice upto 90 days with refrigeration. Similarly, the steam-subjected cane juice (10 and 15 min at 7 psi) could be effectively preserved for upto 30 days with refrigeration, without any preservative.

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The low temperature (LT) conditions that prevail during winter in subtropical regions of India drastically affect the growth and yield of sugarcane. To identify low-temperature-tolerant agronomical acceptable genotypes for immediate deployment as donor parents in the subtropical sugarcane breeding program, 34 sugarcane clones belonging to 7 genetically diverse groups were evaluated under three crop environments, viz., spring planting, winter ratoon and spring ratoon, during 2015–2016 and 2016–2017. In the winter ratoon crop, commercial cane sugar and cane yield were reduced, whereas sucrose % was increased over the spring planted crop and the spring ratoon crop. The wild species and introgressed hybrid groups showed improvement for yield and quality traits in the winter ratoon crop, whereas commercial and near commercial groups showed reduction for these traits over the plant and spring ratoon crops. The tropical cultivars group was the poorest performer irrespective of the traits and crops. Yield per se under a stress environment was adjudged as the best selection criteria. For classification of sugarcane clones according to their low temperature tolerance, an index named winter tolerance index (WTI) is proposed which takes into account the winter sprouting index (WSI), winter growth and yield per se of the winter ratoon crop. The WTI had significant positive association with WSI, cane yield, millable cane population and cane length. As per the WTI ratings, the wild species of Saccharum complex and introgressed hybrid groups were rated as excellent WT clones. Subtropical commercial or advanced generation groups were poor WT clones, and tropical commercial cultivars group were winter sensitive clones. Clones such as AS04-635, AS04-1687, IK76-48, GU07-2276, IND00-1040, IND00-1038 and IND00-1039 had excellent tolerance, and GU07-3849, AS04-245, Co 0238, AS04-2097 and GU07-3774 had good WTI scores. The variety, Co 0238, may be continued for cultivation under LT regions with prophylactic measurers for red rot, while other clones listed above may be utilized in subtropical breeding programs.