There is increasing demand for natural rubber (NR) and there are genuine concerns if the existing rubber plantations in the world will be sufficient to meet its rising global demand. Agro-climatically best suited lands for NR cultivation in almost all major NR producing countries of the world are nearly saturated. Therefore, supply of NR from the traditional areas has also more or less stabilized. NR cultivation is being extended to less suitable lands in non-traditional areas. This paper analyses the thrust areas of future research in natural rubber cultivation in both the traditional and non-traditional regions. Classical breeding and selection during the past 100 years has led to substantial genetic enhancement of Hevea brasiliensis. Molecular breeding and marker assisted selection will be necessary to achieve further significant breakthroughs in genetic enhancement of this tree crop. The need to develop more hardy clones that can tolerate biotic and abiotic stresses is emphasized. Shortening the immaturity period, developing optimal harvesting practices, including scientific use of yield stimulants, sustainability of rubber growing soils, concerns about monoculture and biodiversity, farm mechanization, socio-cultural and economic issues, environmental concerns, climate change etc. are some of the other areas identified for focused research in the years ahead to increase the supply of NR. Developing superior clones and effective extension delivery are central to achieving this objective. The paper concludes by raising certain pertinent questions that beg for immediate answers and with a call for scientists to think out of the box to address newly emerging challenges and opportunities in natural rubber cultivation.

Medical gloves provide an effective barrier to the transmission of human pathogens and help protect both healthcare professionals and patients against contracting infectious diseases. Medical gloves, historically, have been manufactured from natural rubber latex (NRL) tapped from the Brazilian rubber tree (Hevea brasiliensis) because of its excellent barrier properties. However, a processing change in the 1980!s left soluble protein in the glove matrix and huge numbers of people were exposed. Hevea latex proteins in natural rubber elicit anti-Hevea latex protein IgE, an indication that the individual has become "sensitized#. Some individuals who are sensitized to NRL proteins will subsequently experience life-threatening allergic symptoms following a subsequent airborne or contact exposure to latex allergen. The public health risk of Type I latex allergy has led to gloves being made from alternative materials and receiving FDA 510(k) clearance. However, they are not preferred by healthcare providers due to their physical limitations. Natural rubber latex can be produced from many plant species and guayule (Parthenium argentatum) has been commercialized on the basis of its very low protein content, and non-crossreactive latex. This report summarizes and explains the information currently available on the safety of guayule latex and comments on other alternate latex contenders.

Taking pits for planting rubber (Hevea brasiliensis) is one of the most labour intensive and expensive operations in rubber cultivation. A field experiment was conducted at the Central Experiment Station of Rubber Research Institute of India, Chethackal, Pathanamthitta District of Kerala (9o22!N and 76o50!E; 100 m MSL) during the period 2002 to 2008 with the objective to study the effect of pit size on root development and growth of rubber. The soil of the experiment area was sandy clay loam in texture with a depth of around 1m. The treatments were pits of dimensions 45 x 45 x 45 cm, 60 x 60 x 60 cm, 75 x 75 x 75 cm (standard pit size), 90 x 90 x 90 cm, 60 x 60 x 90 cm, 90 x 90 x 60 cm and small pits just sufficient to accommodate polybag plants. Observations over a period of six years indicated that the size of planting pits had no significant effect on development of tap root or lateral roots and growth of rubber. Where the soil was devoid of hard pans, irrespective of the size of the pits, the trees developed a long tap root of length 2.2 to 2.3 m, 6 years after planting. The cost analysis data showed that planting in small pits just sufficient to accommodate the polybag plants could save about 73 per cent of labour cost for pitting compared to the current recommended method of pit size 75 x 75 x 75 cm. The study indicated that planting rubber in small pits, when the soil depth is 1 m or more, did not affect the root development and growth of the plants and by following the method, considerable saving in cost of cultivation could be achieved.

Intercropping in the immature phase of rubber plantations had been the outcome of a major policy decision implemented in 1957 with the core objective of achieving self sufficiency in NR production. However, the priorities and strategies of intercropping have undergone important changes during the past five decades due to a number of factors including changes in the socio-economic determinants, crops grown, objectives and R&D efforts. The study revealed the growing popularity of contract farming of pineapple as intercrop in the immature phase of NR in central Kerala. The results of the analysis highlighted the growing divergence between the recommended and adopted agro-management practices in intercropping of pineapple under contract farming and the potential challenges to the agronomic sustainability of NR cultivation.

In Hevea brasiliensis, since conventional methods of crop improvement are elaborate and time consuming, genetic transformation offers a viable approach to breeders for adding desirable traits in a relatively short period. Although, genetic transformation experiments in Hevea brasiliensis were initiated two decades ago, reports on the development of transgenic plants incorporated with genes coding for agronomically important traits is limited mainly due to the low efficiency of transformation and plant regeneration protocol in Hevea brasiliensis. Therefore the transformation and plant regeneration protocol needs further modifications for developing an efficient and reproducible transgenic plant regeneration system. In the present work, an attempt was made to identify the factors promoting Agrobacterium mediated genetic transformation frequency. The texture and friability of the target tissue (immature anther callus) was improved by pre- culturing it on medium containing varying concentrations of calcium nitrate (0-1200 mg/L). The transformation efficiency was significantly enhanced by using this soft friable callus as target tissue. The combined effect of callus pre-culture and acetosyringone concentration on transformation efficiency was also assessed by incorporating different concentrations of acetosyringone (0-200 mg/L) in the co-culture medium. The transformation frequency was increased from 6 to 14% by using the callus pre-cultured for fifteen days on medium containing 800 mg/L calcium nitrate and increasing the acetosyringone concentration to 80 mg/L in the co-culture medium. The transformation event was confirmed by PCR analysis with MnSOD and nptII gene specific primers. Keywords: Acetosyringone, Call

Somatic embryogenesis is a process by which somatic cells are induced to form bipolar embryos through a series of developmental stages. Since proteins directly influence the cellular metabolism, the changes in protein profile provide a suitable tool for examining the biochemical changes associated with somatic embryogenesis. In plant species, total protein levels increased according to the progression in the developmental stages of somatic embryos and vice versa which in turn correlated with the regeneration potential. In the present study, total soluble proteins were studied during the course of somatic embryogenesis pathway in Hevea as well as at different stages of the development of somatic embryos. SDS-PAGE analysis of total soluble proteins showed marked differences in its profiles. During different stages of somatic embryogenesis pathway, there was more accumulation of proteins in somatic embryos on a tissue fresh weight basis. Three developmental stages of somatic embryos displayed uniform banding pattern for proteins. However, the relative protein content was decreased as the somatic embryos were more advanced in their development, particularly, at the cotyledon stage. This may probably the reason for the low conversion ability of somatic embryos to plantlets and their further establishment.