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Sugarcane is one of the major agro-industrial crops with huge variations in state-wise cane production, productivity and sugar recovery. Twenty-five elite selections of sugarcane clones along with nine commercial checks (early and mid-late maturity group) were evaluated for different cane and sugar yield contributing traits. Analysis of variance revealed significant differences among genotypes along with low ( 20%) genotypic coefficient of variations for all studied traits suggested explicitly the presence of wide variation in genetic material used in the study. All the traits exhibited higher estimates (> 60 %) of heritability (h2b) except sucrose content (26.17 %); while genetic advance (%) of mean was observed low ( 20%) for commercial cane sugar, cane yield, germination, single cane weight, no. of shoots and no. of millable canes. Commercial cane sugar showed significant positive genotypic and phenotypic correlation with germination (%), no. of shoots, no. of millable canes, Stalk length, single cane weight, cane yield and sucrose (%). Cane yield (1.130, 0.995) had highest positive direct effect followed by sucrose (%) (0.308, 0.198). It is suggested that these traits can be considered as main determinant traits. High indirect effects of no. of shoots, no. of millable canes, stalk length, single cane weight through cane yield may be used for indirect selection for improving commercial cane sugar.

Sugarcane on one side considered important for crop diversification and important for human civilization while on other sugar industry is facing a long term losses in terms of monetary issues. Moreover, farmer is also not clear about which techniques is to adopt for practising the sugarcane cultivation for precision farming. Therefore, range of new sugarcane cultivation technologies pertaining to its cultivars, fertilization, weed control, insect-pest and disease control needs to be invented and recommended to the cane farmers. Precision farming is an approach where inputs are utilised in precise amounts to get increased average yields, compared to traditional cultivation techniques. Adoption of precision agriculture in sugarcane has been slow due to a wide range of uncertainties and conflicting opinions. There is need to reduce cost of cultivation and to improve the canes yield and quality by adopting precision sugarcane techniques. In developing countries like India, Pakistan etc. precision agricultural techniques if adopted, is a powerful tool and should be started with a basic, affordable and effective integration of technologies and practices. Present article aims to review published and unpublished information on precision sugarcane farming must be applied for improving the cane yield and quality so as to improve livelihoods of the cane farmers.

Present research was conducted to modify and evaluate commercially available tractor-operated sugarcane trench planter available in Uttar Pradesh as per needs of local conditions prevailing in Punjab for sugarcane cultivation. Prominent modifications included alteration in shape of soil-covering unit and installation of safety grate. During preliminary evaluation, effect of three cutting roller(s) peripheral speeds (0.69 m/s, 0.81 m/s and 0.93 m/s) and three forward speeds (2.26 km/h, 2.6 km/h and 3.0 km/h) was assessed on three popular varieties of sugarcane (Co0118, CoPb93 and CoJ-85) for cane length, cane diameter, sett length, bud damage (%), number of sett cut and sett damage (%). Thereafter, the field evaluation of modified sugarcane trench planter was carried out by selecting one cutting roller(s) peripheral speed (0.69 m/s) and two forward speeds (2.26 km/h and 3.0 km/h) on above varieties. The selected dependent variables were cane length, cane diameter, sett length, bud damage (%), sett damage (%), overlap/gap and germination (%). Results revealed that average sett length increased with the decrease in diameter of cane and cutting roller peripheral speed. However, bud damage (%) increased with the increase in cutting roller peripheral speed. Bud damage (%) in variety Co0118 was higher due to relatively more toughness (hardness) of cane. Average overlapping decreased with the increase in forward speed. Practically, no sett damage was observed in the study. It was found that germination (%) of cane planted by machine was more than the conventional planting. Average germination on 45 DAP (days after planting) on left and right side of trench in different varieties, viz. Co0118, CoPb93 and CoJ-85, were 50.71%, 43.00%, 48.50% and 48.11%, 38.68%, 43.15%, respectively. Economic analysis showed that there was 25.01% reduction in cost of planting and 58.02% reduction in labour cost as compared to conventional method of sugarcane planting followed under Punjab conditions.

Sucrose accumulation in developing sugarcane (Saccharum officinarum) is accompanied by a continuous synthesis and cleavage of sucrose in the storage tissues. It is synthesized in source mature leaves and such assimilates stored in the form of sucrose in the stalks of sugarcane that provide 70% of world sugar. During the phloem transportation, sucrose is unloaded into the sink for metabolism and storage. Its accumulation in sugarcane stalks is affected by sucrose supply, metabolism and sink strength. Sucrose accumulation and carbohydrate metabolism in plant species depend upon activity of Sucrose Synthase (SuSy) enzyme. Fast growing tissues in sugarcane such as root apices, immature stem internodes, cells and tissue cultures usually have low sucrose and higher concentration of SAI (soluble acid invertase) which hydrolyses sucrose into glucose and fructose. The sugar yield needs its enhancement to meet the growing demand for sugar. The photosynthesis activity in source leaves decides the amount of sucrose to sink organs. Sucrose metabolism enzymes control sucrose content in sugarcane stalks. Sucrose accumulation is a complex physiological process controlled by network genes. Recent biochemical and molecular approaches have resolved the various developmental and molecular regulation mechanisms for sucrose accumulation in sugarcane. In this review, discussion have been focussed on molecular involved in sucrose metabolism, source-sink communication and storage, microarray analysis, expressed sequence tags (ESTs) studies, physiological and tissue-specific gene regulation that will help further researches to elucidate the regulatory networks of sucrose accumulation to breed high sugar content in sugarcane.

Sugarcane is an economically important crop and is cultivated throughout the world for its sugar and ethanol. Present sugarcane varieties are derived from inter-specific hybridization between Saccharum officinarum and Saccharum spontaneum, resulting in highly polyploid and aneuploid plants with chromosomes ranging from 80 to 120. This complex nature has hindered advances in marker assisted breeding of this crop. Though an array of methodologies have been adopted by different research groups from all over the world who have well established protocols for developing genetically modified (GM) sugarcane. Several genes of economic interest have been transformed in sugarcane, despite variable success in transgene integration and expression. Recently, genome editing approaches (the zinc finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs) and CRISPR/Cas9 system) have opened new and unique opportunities for researchers to enhance crop production. However, as far as sugarcane is considered, there are still several challenges/constraints (large genome size, polyploidy, low transformation efficiency, transgene silencing and lack of high throughput screening techniques) ahead that deter sugarcane improvement through genetic engineering and need to be resolved to achieve a complete exploitation of the crop through these biotechnological tools. This review is an attempt to unravel the various sugarcane genomic approaches and their applications towards accelerating sugarcane improvement.

This chapter outlines some of the biotechnological developments that are in place and tailored to address important issues related to sugarcane improvement. The major objectives to improve sugarcane crops using conventional and biotechnological techniques include high cane yield potential, early maturity, resistance to lodging, resistance to stress environments, disease resistance, insect resistance and juice quality components. The system is been adopted for improving the quality and production of sugarcane and somaclones for yield, sugar recovery, disease resistance, drought tolerance, and maturity have been isolated. The involvement of MicroRNAs (miRNAs) in abiotic stress has been studied in plants in response to dehydration or sodium chloride by using expression analysis, suggesting stress-specific regulation of expression of miRNA in sugarcane. The drought-tolerant sugarcane varieties can withstand water stress up to 36 days, and under drought stress can yield substantially higher than the control variety BL-19.

Genetic divergence among the twenty four sugarcane genotypes collected from various sugarcane research institutions of northern India were tested in a randomized complete block design with three replicates during the cropping seasons 2013 - 14. The assessment of the genetic diversity was based on the eighteen cane yield and quality characters. The results of the study indicated that, the genotypes were grouped into five clusters based on the genetic distance using Mahalanobis's statistics. Higher inter-cluster distance was recorded between cluster II and V (89.668) indicating high genetic diversity among these two clusters. Thus, exploitation of genotypes within these two clusters as parents for crossing could produce good sugarcane segregants. The lowest intra cluster distance was reported in the cluster III (14.897) revealed that clones are identical and can not to be used as parents in crossing that results hybrid not desirable for the characters studied. A critical analysis of cluster means for different traits indicated that cluster I was desirable for cane yield, CCS (t/ha), single cane weight, stalk diameter, germination (%), cluster II was better for juice extraction percentage, cluster III for better juice purity percent, brix (%), sucrose (%) and CCS (%) for 12 months and cluster V was the best source for NMC (000/ha), stalk length with other good cane and sugar yield traits. The average D

Sugarcane (Saccharum spp. hybrid complex), being an important industrial crop is always under tremendous pressure of improvement in term of cane and sugar yield. Therefore like other crops large number of sugarcane germplasm and breeding material is screened for identification of improved clones. To tackle the problem of limited seed or space, Augmented Block Design was used to screen 112 diverse clones because replications were not required in it. Analysis of variance revealed the significant effects due to checks and varieties for germination, number of shoots at 120 days, number of tillers at 240 days, number of millable canes, single cane weight and cane yield per plot. While the adjusted block effects were non-significant for all traits except, number of tillers at 240 days, number of millable canes and cane diameter indicated homogeneity of evaluation blocks. Similarly, the significant mean square due to checks v/s varieties indicated that the test entries were significantly different from checks. 38 and 12 clones were identified better over check CoPb 92 and CoPb 93 respectively for cane yield. High heritability coupled with high genetic advance was observed for number of shoots at 120 days, number of tillers at 240 days, number of millable cane and cane yield per plot indicated that selection for these characters will be effective for future improvement of clones.

The present study was carried out in Kashmir (India) to assess the genetic variability for grain yield and component traits among 14 red rice ecotypes from temperate region (locally known as Zag for its coloured kernels) and correlation and path coefficients were also studied for fifteen agro-morphological characters. Genotypic and phenotypic coefficients of variation were high for grain yield, secondary branches per panicle and panicle weight; moderate for grain number per panicle, grain length:breadth (L:B) ratio and panicle density. High heritability accompanied by high to moderate genetic advance for panicle density, days to 50% flowering, plant height, grain number indicated the predominance of additive gene action for the expression of these characters. Grain yield was found to be positively and significantly correlated with number of tiller per plant, panicle density m-2 and number of grain per panicle at both genotypic and phenotypic levels indicating the importance of these characters for yield improvement in this material. The results of genotypic path analysis revealed that panicle density had the highest positive direct effect followed by plant height and days to flower. The overall results indicated that selection favouring higher panicle density, test weight and panicle weight and medium plant height with a reasonable balance for moderate grain number would help to achieve higher grain yield in this population of red rice ecotypes.

The nature and magnitude of heterosis and combining ability was studied in 18 F1 hybrids involving three CMS lines and six testers using line × tester analysis. The analysis of variance for combining ability of all the traits showed that variances due to treatments, parents, hybrids were highly significant. The line ‘CRMS 32A’ and testers viz. ‘Super rice-8’, ‘R 1099-2569-1-1’ and ‘Jitpiti’ were identified as good general combiners. The significant differences between lines x testers interaction indicates that SCA attributed heavily in the expression of these traits and demonstrates the importance of dominance or non additive variances for all the traits. The hybrid ‘CRMS 32A’/‘R 1099-2569-1-1’ and ‘APMS 6A’/‘Super rice-8’ were promising for grain yield. The magnitude of relative heterosis, heterobeltiosis and standard heterosis were also estimated for different characters. A high degree of relative heterosis was observed for grain yield (20.45- 82.37%) in the hybrids viz., ‘CRMS 32A’/‘Super rice-8’, ‘APMS 6A’/‘Super rice-8’, ‘APMS 6A’/‘Jitpiti’ and ‘CRMS 32A’/‘R 1099-2569-1-1’. While, a higher degree of: heterobeltiosis (13.60 -68.37%) was observed for grain yield in the hybrids viz., ‘CRMS 32A’/‘Super rice-8’, ‘CRMS 32A’/‘R 1099-2569-1-1’, ‘APMS 6A’/’Super rice-8’ and ‘APMS 6A’/’Jitpiti’. A high degree of standard heterosis was observed for grain yield in the hybrid ‘CRMS 32A’/‘R 1099-2569-1-1’. The hybrid ‘CRMS 32A’/ ‘R 1099-2569-1-1’ recorded a high degree of relative heterosis (62.01%), heterobeltiosis (57.35%) and standard heterosis (15.05 and 25.51% over check hybrids, ‘Mahamaya’ and ‘Indirasona’, respectively) that can be tested on yield trials for its further testing over locations.

The automation of sequencing technologies, flooding in the knowledge of plant-pathogen interactions and advancements in bioinformatics provide tools leading to better knowledge not only of the genome of plant pathogens or microorganism beneficial to plants but also of ways of incorporating genes from microbes into plants as microbial-derived resistance. The identification of various microorganism genes playing key role during pathogensis and the dissection of the signal transduction components of the hypersensitive response and systemic acquired resistance pathways have greatly increased the diversity of options available for tailoring fungus resistant crops. The genetically engineered plants carrying these genes showed spontaneous activation of different defense mechanisms, leading the plant in an elevated state of defense. This �defense mode� greatly enhances the plant�s ability to quickly react to a pathogen invasion and more successfully overcome the infection. The aim of this review is to highlight the dynamic use of genes of microorganisms in enhancing crop tolernace towards fungal intruders by examining the most relevant research in this field.

Tissue culture is one of the tools necessary for genetic engineering and many other breeding programs. Moreover, selection of high regenerating rice varieties is a pre-requisite for success in rice biotechnology. In this report we established a reproducible plant regeneration system through somatic embryogenesis. The explants used for regeneration were embryogenic calli derived from mature seeds cultured on callus induction media. For callus induction mature seeds were cultured on MS medium containing 30 g/l sucrose combined with 560 mg/l proline and 1.5-3.5 mg/l 2,4-D and 0.5-1.5 mg/l Kin. For plant regeneration, embryogenic calli were transferred to MS medium containing 30 g/l sucrose, supplemented with 1.0-3.0 mg/l BAP, 0.5-1.5 mg/l Kin and 0.5-1.5 mg/l NAA. The highest frequency of callus induction (44.4%) was observed on the MS medium supplemented with 2.5 mg/l 2,4-D, 0.5 mg/l Kin, 560 mg/l proline and 30 g/l sucrose. The highest frequency of shoot regeneration (42.5%) was observed on the MS medium supplemented with 2.0 mg/l BAP, 0.5 mg/l NAA and 0.5 mg/l Kin. The plantlets were hardened and transferred to soil in earthen pots. The developed method was highly reproducible. The in vitro developed plants showed normal growth and flowering under glasshouse conditions.

Transgenic science and technology are fundamental to the state-of-art plant molecular genetics and crop improvement. The new generation of technology endeavors to introduce genes 'stably' into 'site-specific' locations and in 'single copy' without the integration of extraneous vector 'backbone' sequences or 'selectable markers'. Numerous plant transformation technologies have developed with the aim of achieving these objectives. Here we discuss some of these technologies, which can push the development of 'better transgenic plants with desirable characters only'.

Viral diseases are a major threat to world agriculture and breeding resistant varieties against these viruses is one of the major challenge faced by plant virologists and biotechnologists. The development of the concept of pathogen derived resistance gave rise to strategies ranging from coat protein based interference of virus propagation to RNA mediated virus gene silencing. Much progress has been achieved in protecting plants against these RNA and DNA viruses. In this review, the most recent transgene based approaches for viral disease management in plants will be discussed.

Development of crop varieties which are resistant against many economically important diseases is a major challenge for plant biotechnologists worldwide. Although much progress in this area has been achieved through classical genetic approaches, this goal can be achieved in a more selective and robust manner with the success of genetic engineering techniques. In this regard, RNA interference (RNAi) has emerged as a powerful modality for battling some of the most notoriously challenging diseases caused by viruses, fungi and bacteria. RNAi is a mechanism for RNA-guided regulation of gene expression in which double-stranded ribonucleic acid (dsRNA) inhibits the expression of genes with complementary nucleotide sequences. The application of tissue-specific or inducible gene silencing in combination with the use of appropriate promoters to silence several genes simultaneously will result in protection of crops against destructive pathogens. RNAi application has resulted in successful control of many economically important diseases in plants.

Knowledge, innovations and practices that are generated in a unique, tradition-based context from indigenous peoples is termed as traditional knowledge that forms an integral part of indigenous peoples’ social, cultural and spiritual values. Access to various biological resources, fair and equitable sharing of benefits from the use of these resources and TK has become an important agenda after the CBD came into force. The debates are still going on the requirement for institutional mechanisms to regulate the access and benefit-sharing agreements, defining ownership of biological resources and their associated TK. With the advent in recent technologies, TK associated with natural biological resources and their economic and scientific importance has attracted a wide range of private sector stakeholders for their utilization. In the past, TK has often been accessed without the consent of the owners of TK and without sharing the benefits arising out of its utilization. Various measures for the protection of TK, through either adapted intellectual property rights or sui generis systems, are in vain as long as the holders of TK and the specific context in which TK has been generated, transmitted and preserved do not enjoy appropriate protection through the recognition of indigenous peoples’ rights. Indigenous rights can gain strength from progress made and legal standards set in international level elaborating measures for the protection of TK and vice versa. This chapter explores and reports the various negotiations on an international regime on access and benefit sharing in the framework of the Convention on Biological Diversity that provides a forum to push indigenous peoples’ right to their TK.

Sugarcane (Saccharum spp.) is a commercially important crop, vulnerable to fungal disease red rot caused by Colletotrichum falcatum Went. The pathogen attacks sucrose accumulating parenchyma cells of cane stalk leading to severe losses in cane yield and sugar recovery. We report development of red rot resistant transgenic sugarcane through expression of β-1,3-glucanase gene from Trichoderma spp. The transgene integration and its expression were confirmed by quantitative reverse transcription-PCR in first clonal generation raised from T0 plants revealing up to 4.4-fold higher expression, in comparison to non-transgenic sugarcane. Bioassay of transgenic plants with two virulent C. falcatum pathotypes, Cf 08 and Cf 09 causing red rot disease demonstrated that some plants were resistant to Cf 08 and moderately resistant to Cf 09. The electron micrographs of sucrose storing stalk parenchyma cells from these plants displayed characteristic sucrose-filled cells inhibiting Cf 08 hyphae and lysis of Cf 09 hyphae; in contrast, the cells of susceptible plants were sucrose depleted and prone to both the pathotypes. The transgene expression was up-regulated (up to 2.0-fold in leaves and 5.0-fold in roots) after infection, as compared to before infection in resistant plants. The transgene was successfully transmitted to second clonal generation raised from resistant transgenic plants. β-1,3-glucanase protein structural model revealed that active sites Glutamate 628 and Aspartate 569 of the catalytic domain acted as proton donor and nucleophile having role in cleaving β-1,3-glycosidic bonds and pathogen hyphal lysis.

Silver Genetic diversity of Colletotrichum falcatum causing red rot of sugarcane was assessed based on morphological, pathological and molecular characteristics especially from sub-tropical Indian conditions. Sixteen isolates of this pathogen were collected based on the extensive survey on prominent varieties grown in the region along with some elite selections. Morphological observations (colony colour, mycelium pattern and sporulation) grouped the isolates into two distinct types (C1: light type and C2: dark type). However, quantitative data on colony diameter showed five clusters for these isolates. Pathogenic characterization of these isolates on fourteen standard differentials formed six groups, ingroup 1: (CF-Pb-1) isolates Cf-157, Cf-249 and Cf-248 were the most virulent while group 6 (CF-Pb-6) isolates Cf-60 and Cf-247 were the least one. The genetic relatedness among the isolates using Random Amplified Polymorphic DNA (RAPD) analysis revealed sufficient molecular polymorphism, which in turn confirmed the variation in virulence of different isolates. The data categorized different isolates into two major clusters and five independent lineages. Polymorphic information content (PIC) ranged from 0.701 to 0.929. Isolate Cf-223 was found to be genetically most diverse among all the isolates. Present study inferred that morphological grouping of most of the isolates showed positive correlation with the pathogenic variability while molecular diversity did not showed such associations.

Combining ability analysis was applied through Line x Tester analysis of 36 hybrids developed by crossing 18 lines (Males) with 2 CMS lines (Females) to learn the genetic architecture of various agro-morphological traits in rice for the development of hybrids under temperate conditions. Analysis of variance revealed significant differences among genotypes, crosses, lines, testers and line x tester interactions for all the traits studied. Preponderance of non-additive gene effects was realized by higher values of specific combining ability compared to general combining ability, ratio of variances of SCA to GCA and average degree of dominance. The proportional contribution of testers was observed to be lower than that of line x tester interactions, thus resulted in higher estimates of SCA variances. The estimates of GCA effects indicated male parent K-08-61-2 was a good general combiner for grain yield per plant and other yield contributing traits and among the female parent SKAU 11A was observed to be a good general combiner. Cross combinations SKAU 7A x K-08-61-2, SKAU 7A x SR-2, SKAU 11A x K08-60-2, SKAU 11A x K-08-59-3 and SKAU 11A x SKAU-389 were found to be good specific combinations for grain yield per plant and other desirable traits, and need to be tested on large scale.

An investigation was undertaken to study the suitability of sugarbeet genotypes and to elucidate their yield related and quality characteristics under subtropical conditions during rabi 2014–2015. Thirteen sugarbeet genotypes were sown in randomized block design (RBD) in a plot size of 36 m2 having three replications and data were recorded for germination (%), shoot length (cm), root length (cm), total length (root + shoot, in cm), shoot weight (kg), root weight (kg), root/shoot ratio, root girth (cm), root volume (cm3), biological yield per plant (kg), harvest index (%), Brix (°), sucrose (%), purity (%) in juice and root yield per plot (kg) were recorded. Analysis of variance was significant for traits viz: germination (%), shoot length, root length, total length, root girth, root volume, Brix (°), sucrose (%), purity (%) and root yield per plot. Germination (%) varied from 60% (Calixta) to 89.67% (Cauvery). Magnolia recorded the highest root length (31.33 cm). The most promising genotype for both root girth (cm) and root volume (cm3) respectively was Cauvery (46.25, 1755.78 cm3). Regarding quality, the superior genotype for Brix (°), sucrose (%) and purity (%) was H10671 (18.00, 15.20 and 84.42, respectively). Cauvery (194.51 kg) ranked first for root yield per plot followed by Indus (165.31 kg) and SV 892 (163.85 kg). The correlation coefficients of different traits with root yield and among themselves showed that there were highly significant and positive associations between root yield with total length. (r=0.416), shoot length (r=0.475), shoot weight (r=0.435), root girth (r=0.605), root volume(r=0.538) and germination (%) (r=0.360) while it was negatively correlated with root length and harvest index. Therefore, these traits should be given emphasis while making selections for high yielding genotypes in sugarbeet. The results revealed that the genotypes/varieties of sugarbeet are capable to produce high amounts of root yield and sugar content however, molecular basis of variability and association among the traits needs to be probed further.

Among the different contaminants in the environment, heavy metals (HMs) are unique due to the fact that they cannot be broken down to non-toxic forms. According to the reports published worldwide, these metals are released into the environment by both natural and anthropogenic sources, especially, mining and industrial activities, and automobile exhausts (for lead). They leach into underground waters, moving along water pathways and eventually depositing in the aquifer, or are washed away by run-off into surface waters thereby, resulting in water and subsequently soil pollution. The HM contamination is increasing day by day because of increase in population, industrialization and urbanization. Therefore, posing a serious threat to health and environment. Researchers worldwide have used different methods for removing these hazardous elements. Although, these methods for cleaning up of contaminated environment including soil and water are usually expensive and do not give optimum results. Currently, phytoremediation is an effective and affordable technology used to remove inactive metals and metal pollutants from contaminated soil and water. It includes phytoextraction, rhizofiltration, phytostabilization, phytovolatization, and phytodegradation/ phytotransformation. This technology is ecofriendly and exploits the ability of plants to remediate pollutants from contaminated sites. More than 400 plant species have been identified to have potential for soil and water remediation. Among them, Thlaspi, Brassica, Sedum alfredii H., and Arabidopsis species have been mostly studied. Our paper aims to cover the causes of HM pollution and phytoremediation technology, including HM uptake mechanism and several reports describing its application at field level.

Plants respond with changes in their pattern of gene expression and protein products when exposed to low tem- peratures. Thus ability to adapt has an impact on the distribution and survival of the plant, and on crop yields. Many spe- cies of tropical or subtropical origin are injured or killed by non-freezing low temperatures, and exhibit various symptoms of chilling injury such as chlorosis, necrosis, or growth retardation. In contrast, chilling tolerant species are able to grow at such cold temperatures. Conventional breeding methods have met with limited success in improving the cold tolerance of important crop plants involving inter-specific or inter-generic hybridization. Recent studies involving full genome profil- ing/sequencing, mutational and transgenic plant analyses, have provided a deep insight of the complex transcriptional mechanism that operates under cold stress. The alterations in expression of genes in response to cold temperatures are fol- lowed by increases in the levels of hundreds of metabolites, some of which are known to have protective effects against the damaging effects of cold stress. Various low temperature inducible genes have been isolated from plants. Most appear to be involved in tolerance to cold stress and the expression of some of them is regulated by C-repeat binding fac- tor/dehydration-responsive element binding (CBF/DREB1) transcription factors. Numerous physiological and molecular changes occur during cold acclimation which reveals that the cold resistance is more complex than perceived and involves more than one pathway. The findings summarized in this review have shown potential practical applications for breeding cold tolerance in crop and horticultural plants suitable to temperate geographical locations.

Hybrid rice technology offers a readily available opportunity to increase the productivity of rice in acceptable manner. In present study, 36 cross combinations developed by crossing two CMS lines with 18 testers in line x tester mating design were evaluated to find out best heterotic combinations in terms of yield and yield components. Assessment of heterosis based on standard checks (SR-1 and Jhelum) of effectively restored cross combinations showed that there was significant heterosis for all the traits except number of filled grains per panicle and the degree of heterosis varied from trait to trait. All combinations that showed superiority over standard checks for grain yield per plant (ranged from 25.88% to 55.70%), also showed significant heterosis for majority of other traits. The best cross combination in terms of grain yield was SKAU7A x K-08-61-2 and for early maturity SKAU11A x SR-2 over check SR-1 only. Cross combinations SKAU 7A x K-08-61-2, SKAU 7A x SR-2, SKAU 11A x K-08-60-2, SKAU 11A x K-08-59-3 and SKAU 11A x SKAU-389 were found to be good specific combinations for grain yield per plant and other desirable traits and need to be tested on large scale for their commercialisation under temperate conditions.