An Overview of Current Status and Future Prospects of Grassland Resource in Sri Lanka

In Sri Lanka, nearly 12,000 km2 of the total land area is under grass (Pemadasa, 1990). Use of grassland for livestock through traditional way goes back a number of centuries. Almost 20% of the countryside of the earth is covered by grassdominated flora, which includes numerous communities (Pemadasa, 1990).The cohesiveness of traditional societies and social groups in livestock rearing led to complete approaches that resulted in appropriate, environmentally sound sustainable technologies in sustainable grassland management. However, due to growing population and mismanagement, Sri Lankan grasslands are deteriorating. Moreover grasslands play key role in livestock production and environment stability. There is a continuing need to maintain a broad spectrum of production and conservation interests in order to ensure the effective and suitable management of the grassland resource (Premaratne et al., 2003). The local grass species have high diversity and environmental adaptability indicating their potential utilization in future improvement programs especially under changing climate. Therefore, the objective of this paper is to review status of local grassland/species with respect to climate, topography and soil types and its improvement potential

Morphological variability, germination ability and survival rate of weedy rice seeds in Ampara and Matara Districts in Sri Lanka

High diversity in morphology and physiology of weedy rice is important resource for rice breeding. Present study was aimed to determine the seed morphological diversity, germination percentage and survival rate of weedy rice populations in Matara and Ampara districts. Significant diversity of seed shape, awn length, hull color and pericarp color was observed. Germination percentage and survival rates were highly variable. Our results showed that great diversity in weedy rice seeds and the favorable characteristics such high germination percentage, high survival ability, own less seeds, proper seed shape and pericarp color can be incorporated into cultivated rice varieties in rice breeding programs

Diversity and in-situ morphological characterization of weedy rice in selected locations of Sri Lanka

Weedy rice (Oryza sativa f. spontanea) of the Poaceae is a weed accompanying rice and is becoming a serious problem in rice growing areas all over the world. Weedy rice populations were first observed in Ampara district in mid 1990‟s in Sri Lanka and now becoming common in most of the rice growing areas. Weedy rice was reported to be progenies of crosses between wild rice and cultivated rice or the product of degradation of cultivated rice. Since weedy rice is considered as a natural hybrid between cultivated rice and wild rice it may be possible to use as a bridge to transfer genes from secondary genepool to cultivated rice. Weedy rice may also contain important genes which can be incorporated into the cultivated varieties. The study was carried out to characterize the weedy rice accessions collected from different locations in terms of diversity in morphological traits. Twenty three locations were taken as the sampling sites from different agro ecological regions and quantitative and qualitative morphological data on plant height, panicle length, number of tillers and panicles, leaf length, awn color and awn size were taken from randomly selected fifty weedy rice individuals. Results revealed that significant difference was observed between Kurunegala (29.4cm) and Matara (37.1cm) for panicle length. Relatively taller weedy rice plants were observed at Ampara (146.9 cm), while Matara (144.2 cm) recorded the shortest. Number of tillers and the number of panicles were not significantly different. Weedy rice plants observed at Ampara (48.1cm) possessed the longest leaves. 68.13% of observed weedy accessions were awning and Ampara (78%) recorded the highest. Awnless plants were observed at Polonnaruwa (37.3%), Puttlam (34%) and Anuradhapura (33.6%) comparatively higher percentages. Information on morphological diversity should be useful for future breeding programmes of rice and proper conservation of genetic diversity in the adapted germplas

Evaluation of resistance of wild rice; Oryza nivara to feeding by Brown planthopper [Nilaparvata lugens (Stal)] populations

The Brown planthopper (BPH), Nilaparvata lugens is one of the most destructive monophagous insect pests of rice in Sri Lanka. The present study evaluated the level of resistance of seventeen O. nivara accessions collected from different locations in Sri Lanka (WRAC 01, 02, 04, 07, 11, 12, 14, 19, 21, 22, 24, 25, 35, 41, 46, 62 and 9864) to feeding by different BPH populations. Response of test accessions to feeding was assessed by using standard honeydew test. Randomized Complete Block Design with four replicates was applied for the test and repeated two times. Two BPH populations collected from Bathalagoda, Bombuwala which were reared on Bg 380 (susceptible check) and a virulent BPH population collected from Kegalle area and reared on Bg 379/2 (moderately resistant check) were used for screening. Also, to inspect genetic variation among BPH populations by Standard Seed Box Screening test, a differential set of four resistant cultivars with known resistant genes for BPH (Ptb 33- bph2, Bph3; Rathu Hennati - Bph 3; Baba wee - bph4 and Pokkali-Bph9) were used. According to the results, certain accessions of O. nivara (WRAC 35, 21, and 02) showed significantly the least honeydew productions (α= 0.05) indicating their superior resistance to all BPH populations over Ptb 33 (resistant check). WRAC 01 and Ptb 33 grouped together for their resistance, while WRAC 25, 04, 22, 14, 07, 24 and 9864 showed significantly less honeydew productions compared to moderately resistant variety Bg 379/2 indicating their considerable level of resistance to BPH. Bg 380 showed the highest honeydew production indicating no resistance to BPH in it. Significantly the highest, moderate and lowest honeydew excretions were produced by Kegalle, Bathalagoda and Bombuwela populations respectively. Differential responses to standard resistant cultivars revealed genetic variation of Kegalle population from other two populations studied. Also, virulent nature of Kegalle population was detected for bph 4 gene

Evaluation of turmeric-mung bean intercrop productivity through competition functions

An intercropping experiment was conducted with varying combinations of turmeric and mung bean to find out the efficacy of productivity and economic return through competition functions. Treatments were evaluated on the basis of several competition functions, such as land equivalent ratio (LER), aggressiveness, competitive ratio (CR), monetary advantage index (MAI) and system productivity index (SPI). Results showed that rhizome yields of turmeric were higher in intercropping system than in mono crop. It indicated that intercropping of mung bean did not affect the rhizome yield of turmeric. However, turmeric (100 %) + 3 row mung bean (100 %) in between turmeric lines intercropping system exhibited maximum yield of both the crops as well as turmeric equivalent yield, LER, competitive indices values, SPI and MAI (Tk. 2,44,734.46 ha-1) compared to the other intercropping combinations and the mono crops. Aggressiveness of intercrop indicated dominance of turmeric over mung bean in all the combinations except turmeric (100 %) + 1 row mung bean (33 %). Competition functions of intercroping suggested beneficial association of turmeric and mung bean crops. The study revealed that mung bean could be introduced as intercrop with turmeric without hampering rhizome yield with higher benefit additionally increasing mung bean production area. © 2018 University of Ljubljana. All rights reserved

Dietary species richness as a measure of food biodiversity and nutritional quality of diets

Biodiversity is key for human and environmental health. Available dietary and ecological indicators are not designed to assess the intricate relationship between food biodiversity and diet quality. We applied biodiversity indicators to dietary intake data from and assessed associations with diet quality of women and young children. Data from 24-hour diet recalls (55% in the wet season) of n = 6,226 participants (34% women) in rural areas from seven lowand middle-income countries were analyzed. Mean adequacies of vitamin A, vitamin C, folate, calcium, iron, and zinc and diet diversity score (DDS) were used to assess diet quality. Associations of biodiversity indicators with nutrient adequacy were quantified using multilevel models, receiver operating characteristic curves, and test sensitivity and specificity. A total of 234 different species were consumed, of which < 30% were consumed in more than one country. Nine specieswere consumed in all countries and provided, on average, 61% of total energy intake and a significant contribution of micronutrients in the wet season. Compared with Simpson's index of diversity and functional diversity, species richness (SR) showed stronger associations and better diagnostic properties with micronutrient adequacy. For every additional species consumed, dietary nutrient adequacy increased by 0.03 (P < 0.001). Diets with higher nutrient adequacy were mostly obtained when both SR and DDS were maximal. Adding SR to the minimum cutoff for minimum diet diversity improved the ability to detect diets with higher micronutrient adequacy in women but not in children. Dietary SR is recommended as the most appropriate measure of food biodiversity in diets

Phytohormones as Growth Regulators During Abiotic Stress Tolerance in Plants

Phytohormones (PHs) play crucial role in regulation of various physiological and biochemical processes that govern plant growth and yield under optimal and stress conditions. The interaction of these PHs is crucial for plant survival under stressful environments as they trigger signaling pathways. Hormonal cross regulation initiate a cascade of reactions which finely tune the physiological processes in plant architecture that help plant to grow under suboptimal growth conditions. Recently, various studies have highlighted the role of PHs such as abscisic acid, salicylic acid, ethylene, and jasmonates in the plant responses toward environmental stresses. The involvement of cytokinins, gibberellins, auxin, and relatively novel PHs such as strigolactones and brassinosteroids in plant growth and development has been documented under normal and stress conditions. The recent identification of the first plant melatonin receptor opened the door to this regulatory molecule being considered a new plant hormone. However, polyamines, which are not considered PHs, have been included in this chapter. Various microbes produce and secrete hormones which helped the plants in nutrient uptake such as N, P, and Fe. Exogenous use of such microbes help plants in correcting nutrient deficiency under abiotic stresses. This chapter focused on the recent developments in the knowledge related to PHs and their involvement in abiotic stresses of anticipation, signaling, cross-talk, and activation of response mechanisms. In view of role of hormones and capability of microbes in producing hormones, we propose the use of hormones and microbes as potential strategy for crop stress management.Fil: EL Sabagh, Ayman. Scientific And Technological Research Council Of Turkey; TurquíaFil: Islam, Mohammad Sohidul. Kafrelsheikh University; EgiptoFil: Hossain, Akbar. Hajee Mohammad Danesh And Technology University; BangladeshFil: Iqbal, Muhammad Aamir. University Of Poonch; PakistánFil: Mubeen, Mohammad. Comsats University Islamabad; PakistánFil: Waleed, Mirza. Comsats University Islamabad; PakistánFil: Reginato, Mariana Andrea. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones Agrobiotecnológicas. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Agrobiotecnológicas; ArgentinaFil: Battaglia, Martin. Cornell University; Estados UnidosFil: Ahmed, Sharif. International Rice Research Institute; FilipinasFil: Rehman, Abdul. The Islamia University Of Bahawalpur; PakistánFil: Arif, Muhammad. The University Of Agriculture; PakistánFil: Athar, Habib-Ur-Rehman. Bahauddin Zakariya University; PakistánFil: Ratnasekera, Disna. University Of Ruhuna; Sri LankaFil: Danish, Subhan. Bahauddin Zakariya University; PakistánFil: Raza, Ali. Sichuan Agricultural University; ChinaFil: Rajendran, Karthika. Vellore Institute Of Technology; IndiaFil: Mushtaq, Muntazir. Icar-national Bureau Of Plant Genetic Resources; IndiaFil: Skalicky, Milan. Czech University Of Life Sciences Prague; República ChecaFil: Brestic, Marian. Czech University Of Life Sciences Prague; República ChecaFil: Soufan, Walid. King Saud University; Arabia SauditaFil: Fahad, Shah. University Of Haripur; PakistánFil: Pandey, Saurabh. Guru Nanak Dev University; IndiaFil: Abdelhamid, Magdi T.. National Research Centre Dokki; Egipt

Consequences and Mitigation Strategies of Heat Stress for Sustainability of Soybean (<em>Glycine max</em> L. Merr.) Production under the Changing Climate

Increasing ambient temperature is a major climatic factor that negatively affects plant growth and development, and causes significant losses in soybean crop yield worldwide. Thus, high temperatures (HT) result in less seed germination, which leads to pathogenic infection, and decreases the economic yield of soybean. In addition, the efficiency of photosynthesis and transpiration of plants are affected by high temperatures, which have negative impact on the physio-biochemical process in the plant system, finally deteriorate the yield and quality of the affected crop. However, plants have several mechanisms of specific cellular detection of HT stress that help in the transduction of signals, producing the activation of transcription factors and genes to counteract the harmful effects caused by the stressful condition. Among the contributors to help the plant in re-establishing cellular homeostasis are the applications of organic stimulants (antioxidants, osmoprotectants, and hormones), which enhance the productivity and quality of soybean against HT stress. In this chapter, we summarized the physiological and biochemical mechanisms of soybean plants at various growth stages under HT. Furthermore, it also depicts the mitigation strategies to overcome the adverse effects of HT on soybean using exogenous applications of bioregulators. These studies intend to increase the understanding of exogenous biochemical compounds that could reduce the adverse effects of HT on the growth, yield, and quality of soybean

Potential Role of Plant Growth Regulators in Administering Crucial Processes Against Abiotic Stresses

Plant growth regulators are naturally biosynthesized chemicals in plants that influence physiological processes. Their synthetic analogous trigger numerous biochemical and physiological processes involved in the growth and development of plants. Nowadays, due to changing climatic scenario, numerous biotic and abiotic stresses hamper seed germination, seedling growth, and plant development leading to a decline in biological and economic yields. However, plant growth regulators (PGRs) can potentially play a fundamental role in regulating plant responses to various abiotic stresses and hence, contribute to plant adaptation under adverse environments. The major effects of abiotic stresses are growth and yield disturbance, and both these effects are directly overseen by the PGRs. Different types of PGRs such as abscisic acid (ABA), salicylic acid (SA), ethylene (ET), and jasmonates (JAs) are connected to boosting the response of plants to multiple stresses. In contrast, PGRs including cytokinins (CKs), gibberellins (GAs), auxin, and relatively novel PGRs such as strigolactones (SLs), and brassinosteroids (BRs) are involved in plant growth and development under normal and stressful environmental conditions. Besides, polyamines and nitric oxide (NO), although not considered as phytohormones, have been included in the current review due to their involvement in the regulation of several plant processes and stress responses. These PGRs are crucial for regulating stress adaptation through the modulates physiological, biochemical, and molecular processes and activation of the defense system, upregulating of transcript levels, transcription factors, metabolism genes, and stress proteins at cellular levels. The current review presents an acumen of the recent progress made on different PGRs to improve plant tolerance to abiotic stress such as heat, drought, salinity, and flood. Moreover, it highlights the research gaps on underlying mechanisms of PGRs biosynthesis under stressed conditions and their potential roles in imparting tolerance against adverse effects of suboptimal growth conditions.Fil: Sabagh, Ayman EL. Kafrelsheikh University; EgiptoFil: Mbarki, Sonia. National Institute Of Research In Rural Engineering; TúnezFil: Hossain, Akbar. Bangladesh Agricultural Research Institute; BangladeshFil: Iqbal, Muhammad Aamir. University Of Poonch Rawalakot; PakistánFil: Islam, Mohammad Sohidul. Hajee Mohammad Danesh And Technology University; BangladeshFil: Raza, Ali. Fujian Agriculture And Forestry University; ChinaFil: Llanes, Analia Susana. Universidad Nacional de Rio Cuarto. Facultad de Cs.exactas Fisicoquimicas y Naturales. Instituto de Investigaciones Agrobiotecnologicas. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Cordoba. Instituto de Investigaciones Agrobiotecnologicas.; ArgentinaFil: Reginato, Mariana Andrea. Universidad Nacional de Rio Cuarto. Facultad de Cs.exactas Fisicoquimicas y Naturales. Instituto de Investigaciones Agrobiotecnologicas. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Cordoba. Instituto de Investigaciones Agrobiotecnologicas.; ArgentinaFil: Rahman, Md Atikur. Grassland And Forage Division National Institute; Corea del SurFil: Mahboob, Wajid. Nuclear Institute Of Agriculture,; PakistánFil: Singhal, Rajesh Kumar. Indian Council Of Agricultural Research; IndiaFil: Kumari, Arpna. Guru Nanak Dev University; IndiaFil: Rajendran, Arvind. Vellore Institute Of Technology; IndiaFil: Wasaya, Allah. Bahauddin Zakariya University; PakistánFil: Javed, Talha. Fujian Agriculture And Forestry University; JapónFil: Shabbir, Rubab. University Of Poonch Rawalakot; PakistánFil: Rahim, Junaid. University Of Çukurova; PakistánFil: Barutçular, Celaleddin. Institute Of Crop Science And Resource Conservation; AlemaniaFil: Habib Ur Rahman, Muhammad. Sichuan Agricultural University; ChinaFil: Raza, Muhammad Ali. Sichuan Agricultural University; ChinaFil: Ratnasekera, Disna. University Of Ruhuna; Sri LankaFil: Konuskan l, Ömer. Mustafa Kemal University; TurquíaFil: Hossain, Mohammad Anwar. Bangladesh Agricultural Research Institute; BangladeshFil: Meena, Vijay Singh. Indian Council Of Agricultural Research; IndiaFil: Ahmed, Sharif. Bangladesh Agricultural Research Institute; BangladeshFil: Ahmad, Zahoor. Bangladesh Wheat And Maize Research Institute; BangladeshFil: Mubeen, Muhammad. Sichuan Agricultural University; ChinaFil: Singh, Kulvir. Punjab Agricultural University; IndiaFil: Skalicky, Milan. Czech University Of Life Sciences Prague; República ChecaFil: Brestic, Marian. Slovak University Of Agriculture; EslovaquiaFil: Sytar, Oksana. Slovak University Of Agriculture; EsloveniaFil: Karademir, Emine. Siirt University; TurquíaFil: Karademir, Cetin. Siirt University; TurquíaFil: Erman, Murat. Siirt University; TurquíaFil: Farooq, Muhammad. College Of Agricultural And Marine Sciences Sultan; Omá

RELATIONSHIPS BETWEEN GRAIN YIELD AND PHYSIOLOGICAL TRAITS OF DURUM WHEAT VARIETIES UNDER DROUGHT AND HIGH TEMPERATURE STRESS IN MEDITERRANEAN ENVIRONMENTS

WOS: 000405360700074Drought and associated high temperatures are the major environmental stresses limiting wheat productivity in Mediterranean region. To evaluate the physiological and yield responses of durum wheat varieties under high temperature and drought stress in Mediterranean region, 15 durum wheat cultivars were grown in two consecutive years (2007-08 and 2008-09). The varieties were grown under two temperature regimes viz. normal temperature (normal sowing time) and high temperature (late sowing time), and/with two water regimes viz. rain fed (RF) and supplement irrigation (SI) conditions. Our results indicated that at rain-fed environment (water stress) caused a significant reduction in physiological parameters and grain yield. Water stress reduced 30.0 and 13.8% grain yield in 2007-08 and 2008-09, respectively. Warm environment (heat stress) caused significant reductions in physiological parameters and grain yield of 54 and 32% in 2007-08 and 2008-09, respectively. Hence, delayed sowing associated with high temperature resulted in an overall decrease in grain yield. Significant differences in grain yield was found among the varieties. Based on the growth traits and economic-yield, the cool irrigated environment is most suitable followed by the environment in cool rain-fed. However, the variety Balcah-2000 and Fuatbey-2000 achieved the highest yield under cool well-watered conditions and hence best for grown under well-watered cropping systems. Grain yield was strongly correlated with SPAD value in cool environment (RF) while, negative correlation in warm conditions (RF). On the other hand, grain yield was strongly correlated with specific leaf weight (SLW) value in cool environment (RF). A negative correlation between grain yield and flag leaf nitrogen content (FLNC) was observed under warm conditions (RF). A positive and significant correlation between SLW and FLNC was recorded under warm conditions (RF). The ash content (AC) has a positive correlation with FM in cool environment (SI). A positive and significant correlation between FLNC and SPAD under cool (SI) and warm (Rf) conditions. The chlorophyll fluorescence contributes significantly to yield stability under stressed environments. Positive correlations of chlorophyll with grain yield make it possible to evaluate genotypes with high yield stability and consequently, can be used as a selection criterion to identify the environment stress tolerance of wheat genotypes. Balcah-2000 and Solen-2002 cultivars are potentially good candidates for producing good yield in the hot and dry climates in Mediterranean conditions.Scientific Research Project Center of Cukurova University Turkey [ZF2007BAP26]This work was supported by grants from Scientific Research Project Center of Cukurova University (ZF2007BAP26), Turkey