Eight cycles of half-sib family recurrent selection to improve rubber yield in russian dandelion

Author(s):  
David Wolyn ◽  
Gregory Innes

Russian dandelion (Taraxacum kok-saghyz) produces natural rubber which can complement the world’s supply of this strategic commodity, derived mainly from the Para rubber tree (Hevea brasiliensis). Four cycles of half-sib family recurrent selection conducted previously in russian dandelion improved rubber yield nearly 50%. The objectives of this research were to continue selection for four additional cycles and evaluate progress from eight generations of breeding, and assess the potential for future gains. Rubber yield increased from 0.205 to 0.378 g/plant from Cycle 0 (C0) to C8, representing an 84% improvement, or 10% per cycle. Increases from C0 to C4 were similar to those from C4 to C8. Root dry weight did not increase from selection and improved yield only resulted from enhancing rubber percentage which changed from 4.35 to 7.62%. Selection response has not plateaued and phenotypic variation has not decreased, indicating continued gains can occur with additional breeding.

2017 ◽  
Vol 142 (6) ◽  
pp. 470-475 ◽  
Author(s):  
Katrina J.M. Hodgson-Kratky ◽  
Olivier M. Stoffyn ◽  
David J. Wolyn

Russian dandelion [Taraxacum kok-saghyz (TKS)] is a promising alternative to the Para rubber tree (Hevea brasiliensis) as a source of natural rubber; however, rubber yields must be improved for this undomesticated species to become a profitable new crop. Half-sib family recurrent selection was conducted for four cycles to increase rubber yield, estimated as the product of rubber percentage, and root dry weight per plant. Two distinct populations were developed for adaptation to sand and loam soil types. Rubber percentage increased from 4.17% for the cycle 0 (C0) population to 6.40% for the C4-loam population. Rubber yield also increased from 0.15 to 0.22 g/plant after four selection cycles. Although phenotypic variation was observed, selection had no effect on root weight; all populations averaged 3.70 g/plant. Rubber yield and percentage and root dry weight were not increased after four selection cycles on sandy soils, likely because of poor adaptation and high environmental variation. Year and soil type affected rubber yields; however, rubber percentage was more stable than root dry weight. Overall, russian dandelion can be improved for rubber yield, and further studies with increased error control should be considered to enhance root dry weight.


Biomics ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 449-454
Author(s):  
B.R. Kuluev ◽  
G.R. Gumerova ◽  
A.V. Knyazev ◽  
Kh.G. Musin ◽  
A.V. Chemeris

Kok-saghyz (Taraxacum kok-saghyz Rodin) is an alternative to Hevea brasiliensis source of high quality natural rubber that is able to grow in temperate climates. However, the field cultivation of kok-saghyz is associated with a number of problems, such as the need for seed stratification, seedlings that are very sensitive to stress factors, laboriousness in the fight against weeds and pests, uneven maturation of seeds, the lack of special equipment for sowing, collecting roots and seeds. In this regard, the use of hairy roots of kok-saghyz as a raw material for obtaining natural rubber seems to be promising. The aim of our work was to obtain cultures of hairy roots of kok-saghyz and to determine the content of natural rubber in them by the hexane method. In the course of the work, 10 lines of hairy roots of kok-saghyz were obtained, capable of growing in isolated cultures. It has been shown that these hairy roots accumulate an average of 7.5% hexane extract (rubber-like substances) per dry weight, which is about 1.5 times more than the roots of field kok-saghyz. Our data indicate that the use of the hairy roots of kok-saghyz is promising for the industrial production of natural rubber.


1994 ◽  
Vol 67 (3) ◽  
pp. 537-548 ◽  
Author(s):  
Abdul Aziz S. A. Kadir

Abstract This paper will attempt to highlight the various advances made to date in the production and processing of natural rubber (NR). The commercially planted rubber tree, Hevea brasiliensis, can yield as high as 3,000 kg of rubber per hectare in contrast to the 500 kg rubber per hectare obtained from the wild Amazonian rubber trees. The high yield of commercial rubber trees is attributed to the successful breeding program, efficient development of agronomic and crop management practices and proper exploitation systems. Today, the Hevea brasiliensis trees not only contribute to the supply of world natural rubber, but also to the ever increasing demand of tropical timber. Latex extracted from the rubber tree is processed to meet the specific requirements of the consumers. In the area of processing, emphasis is on the production of NR as an industrial raw material with improved quality and consistency. Efforts are also placed on processing efficiency, optimum product mix and production of value added modified NR such as epoxidized and deproteinized NR. The processing activities also take into consideration the control of processing effluent with appropriate effluent treatments or conversion of effluent to useful materials.


2021 ◽  
Vol 12 ◽  
Author(s):  
Chen Liang ◽  
Bei Zhang ◽  
Yun Zhou ◽  
Hongyan Yin ◽  
Bang An ◽  
...  

The rubber tree (Hevea brasiliensis) is a tropical perennial crop for the primary source of natural rubber. Colletotrichum gloeosporioides from Hevea brasiliensis (C. gloeosporioides Hb) and Colletotrichum acutatum from Hevea brasiliensis (C. acutatum Hb) are the causal agents of rubber tree anthracnose and lead to serious loss of natural rubber production. Inoculation tests showed that C. gloeosporioides Hb possessed higher pathogenicity than C. acutatum Hb to the rubber tree. Genomic analysis revealed that an unknown gene, named CgNPG1 (a Novel Pathogenic Gene 1), was presented in the genome of C. gloeosporioides Hb but not identified in C. acutatum Hb. CgNPG1 was predicted to encode a small secretory protein without any conserved domain. To investigate the functions of CgNPG1 in C. gloeosporioides Hb and in C. acutatum Hb, the gene deletion and overexpression mutants were generated. The phenotype analysis showed that deletion of CgNPG1 led to changed conidia morphology, decreased mycelial growth, conidiation, conidia germination rate, appressorium formation rate, and pathogenicity of C. gloeosporioides Hb to the rubber tree. Meanwhile, heterogeneous expression of CgNPG1 in C. acutatum Hb significantly changed the conidia morphology and improved the mycelial growth rate, conidiation, conidia germination rate, appressorium formation rate, and the pathogenicity of C. acutatum Hb to the rubber tree. Consistently, CgNPG1 increased the expression level of CaCRZ1 and CaCMK1 in C. acutatum Hb. These data suggested that CgNPG1 contributed to mycelial growth, conidiation, the development of invasive structures, and the pathogenicity of Colletotrichum to the rubber tree, which might be related to the modulation of CaCRZ1 and mitogen-activated protein kinase CMK1. Our results provided new insight into CgNPG1 in regulating growth and pathogenicity of the Colletotrichum spp.


Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 5110
Author(s):  
Sung Woo Bae ◽  
Sunghee Jung ◽  
Sang Chul Choi ◽  
Mi Young Kim ◽  
Stephen Beungtae Ryu

Natural rubber is usually synthesized in the rubber particles present in the latex of rubber-producing plants such as the Pará rubber tree (Hevea brasiliensis) and rubber dandelion (Taraxacum kok-saghyz). Since the detailed lipid compositions of fresh latex and rubber particles of the plants are poorly known, the present study reports detailed compound lipid composition, focusing on phospholipids and galactolipids in the latex and rubber particles of the plants. In the fresh latex and rubber particles of both plants, phospholipids were much more dominant (85–99%) compared to galactolipids. Among the nine classes of phospholipids, phosphatidylcholines (PCs) were most abundant, at ~80%, in both plants. Among PCs, PC (36:4) and PC (34:2) were most abundant in the rubber tree and rubber dandelion, respectively. Two classes of galactolipids, monogalactosyl diacylglycerol and digalactosyl diacylglycerol, were detected as 12% and 1%, respectively, of total compound lipids in rubber tree, whereas their percentages in the rubber dandelion were negligible (< 1%). Overall, the compound lipid composition differed only slightly between the fresh latex and the rubber particles of both rubber plants. These results provide fundamental data on the lipid composition of rubber particles in two rubber-producing plants, which can serve as a basis for artificial rubber particle production in the future.


REPORTS ◽  
2020 ◽  
Vol 6 (334) ◽  
pp. 42-48
Author(s):  
K.R. Uteulin ◽  
◽  
K.Zh. Zhambakin ◽  

This article presents biological features, botanical description, and the results of the anatomical and physiological study of the Dandelion kok-saghyz (Taraxacum kok-saghyz Rodin), a valuable resource plant of world significance. Kok-saghyz is used as a technical culture, a source of high-quality rubber. Natural rubber is widely used in the rubber industry for the production of tires for automobiles, aircrafts, bicycles, as well as shoes, medical gloves and other products. The global rubber industry faces the real danger of the destruction of plantations of the main source of natural rubber - the rubber tree of hevea (Hevea brasiliensis), grown in the tropical humid climate of Southeast Asia, due to its diseases. This has happened in South America, which was originally a world center for the production of natural rubber; it has completely lost its position due to epiphytotics. There is currently a phytosanitary quarantine and a person who was accessed to hevea in South America should not visit the countries of Southeast Asia. Thus, there is a need for reserve additional plant species, the sources of natural rubber in the temperate zone, being adverse for acclimatization of hevea. Dandelion kok-saghyz is recognized as such a promising producer of natural rubber. According to data published, rubber of kok-saghyz sits in the latex vessels of the root, and the rubber content (6 to 14%) depends on the number of circles of the latex vessels (3 to 14). The number of circles of the latex vessels and, therefore, the rubber content in the roots depends on genotype, agricultural background and stage of kok-saghyz ontogenesis. The roots of kok-saghyz are known for high variability in the rubber content even in the same natural population of wild kok-saghyz from 0 to 47.87; 35.85 and 23.58% of the air-dry weight is due to several one-year covers in the root. Kok-saghyz is a highly polymorphic species that can be used in breeding programs. Individual selection provides for the high rubber content in the roots of kok-saghyz (10 to 14%). Currently, kok-saghyz is an important rubber plant with the following features: 1) high percentage of rubber; 2) flowering and fruiting in the first year of life; 3) high quality rubber. Kok-saghyz polymorphism provides for the selection of the most rubber-bearing and most precocious forms of this plant.


Author(s):  
Nayrim Brizuela Guerra ◽  
Giovana Sant'Ana Pegorin ◽  
Miguel Henrique Boratto ◽  
Natan Roberto de Barros ◽  
Carlos Frederico de Oliveira Graeff ◽  
...  

2022 ◽  
Vol 12 ◽  
Author(s):  
Hui-Liang Li ◽  
Ying Wang ◽  
Dong Guo ◽  
Jia-Hong Zhu ◽  
Shi-Qing Peng

The rubber tree (Hevea brasiliensis Muell. Arg.) is a tropical tree species that produce natural rubber. Self-rooted juvenile clones (SRJCs) are novel rubber tree planting materials developed through primary somatic embryogenesis. SRJCs have a higher rubber yield compared with donor clones (DCs). The molecular basis underlying increased rubber yield in SRJCs remains largely unknown. Here, the latex from SRJCs and DCs were collected for strand-specific and small RNA-seq methods. A total of 196 differentially expressed long noncoding RNAs (DELs), and 11 differentially expressed microRNAs were identified in latex between SRJCs and DCs. Targeted genes of DELs were markedly enriched for various biological pathways related to plant hormone signal transduction, photosynthesis, glutathione metabolism, and amino acids biosynthesis. DELs probably acted as cis-acting regulation was calculated, and these DELs relevant to potentially regulate rubber biosynthesis, reactive oxygen species metabolism, and epigenetic modification. Furthermore, the DELs acting as microRNA targets were studied. The interaction of microRNA and DELs might involve in the regulation of natural rubber biosynthesis.


2014 ◽  
Vol 1 (3) ◽  
pp. 133
Author(s):  
Handi Supriadi ◽  
Yulius Ferry

<p>Peremajaan tanaman karet (Hevea brasiliensis) memberikan konsekuensi menurunnya cadangan karbon sehingga diperlukan teknik untuk meminimalisasi kehilangan tersebut. Penelitian bertujuan menganalisis perubahan cadangan karbon pada penebangan tanaman karet tua sebanyak 30%, 50%, 70%, dan 100% yang diikuti oleh penanaman karet muda dengan tanaman sela (jagung dan kacang tanah). Penelitian dilaksanakan bulan Januari sampai Desember 2013 pada pertanaman karet rakyat umur 25 tahun di Kecamatan Way Tuba, Kabupaten Way Kanan, Lampung. Rancangan yang digunakan adalah acak kelompok dengan tiga ulangan. Perlakuan yang diuji adalah penebangan tanaman karet tua 30%, 50%, 70%, dan 100% yang masing-masing diikuti dengan penanaman karet muda dan tanaman sela (jagung dan kacang tanah). Variabel yang diamati: (1) bobot segar dan kering (biomassa); (2) kandungan karbon terikat (fixed carbon); dan (3) cadangan karbon pada pertanaman karet, jagung, kacang tanah, dan tanaman karet muda. Hasil penelitian menunjukkan penebangan karet sebanyak 30%–100% dari populasi menurunkan cadangan karbon sebesar 7,4–24,29 ton C/ha. Penanaman karet muda dan tanaman sela (jagung dan kacang tanah) dapat berkontribusi terhadap penambahan karbon sebesar 0,98-3,28 ton C/ha sehingga kehilangan karbon akibat penebangan tanaman karet tua berkurang menjadi 6,29–22,92 ton C/ha.</p><p>Kata kunci: Hevea brasiliensis, peremajaan, cadangan karbon, tanaman sela</p><p>Rejuvenation of rubber tree (Hevea brasiliensis) can lead to a reduction of carbon stocks. Therefore, appropriate methods are needed to minimize such losses. The objective of this study was to analyze the changes on carbon stocks in the rejuvenation of rubber with logging system of 30%, 50%, 70%, and 100% and intercrops between the young rubber plantation (maize and peanuts). The research was conducted from January to December 2013 at smallholder rubber plantation in Way Tuba District, Way Kanan Regency, Lampung when the trees were 25 years old. The design used was a randomized block design with three replications. The tested treatments were logging of old rubber plants at 30%, 50%, 70%, and 100%, which then followed by planting of young rubber plants and intercropped (maize and peanut). The variables measured were: (1) fresh weight and dry weight (biomass); (2) fixed carbon content; and (3) carbon stocks on rubber plantation, maize, peanuts, and young rubber plants. The results showed that rubber logging at about 30%–100% could reduce carbon stocks by 7.4–24.29 ton C/ha. However, planting of young rubber plants as well as intercropped (maize and peanut) may contributed to the carbon enrichment up to 0.98-3.28 ton C/ha. Hence, the loss of carbon due to logging system turn out to be 6.29–22.92 ton C/ha.</p>


Author(s):  
K.H. Widdup ◽  
T.L. Knight ◽  
C.J. Waters

Slow establishment of caucasian clover (Trifolium ambiguum L.) is hindering the use of this legume in pasture mixtures. Improved genetic material is one strategy of correcting the problem. Newly harvested seed of hexaploid caucasian clover germplasm covering a range of origins, together with white and red clover and lucerne, were sown in 1 m rows in a Wakanui soil at Lincoln in November 1995. After 21 days, the caucasian clover material as a group had similar numbers of emerged seedlings as white clover and lucerne, but was inferior to red clover. There was wide variation among caucasian clover lines (48-70% seedling emergence), with the cool-season selection from cv. Monaro ranked the highest. Recurrent selection at low temperatures could be used to select material with improved rates of seedling emergence. Red clover and lucerne seedlings produced significantly greater shoot and root dry weight than caucasian and white clover seedlings. Initially, caucasian clover seedlings partitioned 1:1 shoot to root dry weight compared with 3:1 for white clover. After 2 months, caucasian clover seedlings had similar shoot growth but 3 times the root growth of white clover. Between 2 and 5 months, caucasian clover partitioned more to root and rhizome growth, resulting in a 0.3:1 shoot:root ratio compared with 2:1 for white clover. Both clover species had similar total dry weight after 5 months. Unhindered root/ rhizome devel-opment is very important to hasten the establishment phase of caucasian clover. The caucasian clover lines KZ3 and cool-season, both selections from Monaro, developed seedlings with greater shoot and root growth than cv. Monaro. KZ3 continued to produce greater root growth after 5 months, indicating the genetic potential for improvement in seedling growth rate. Different pasture estab-lishment techniques are proposed that take account of the seedling growth characteristics of caucasian clover. Keywords: establishment, genetic variation, growth, seedling emergence, Trifolium ambiguum


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