scholarly journals Introgression of Big Vein Tolerance from Lactuca virosa L. into Cultivated Lettuce (Lactuca sativa L.)

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 881C-881 ◽  
Author(s):  
Ryan J. Hayes* ◽  
Ed Ryder ◽  
Bert Robinson

Big vein (BV) disease of lettuce is caused by soil borne fungal vectored viruses, and reduces marketability through head deformation. Tolerant cultivars reduce BV frequency, but no resistant cultivars exist. L. virosa L. is highly resistance. The objectives were to 1) determine if L. virosa P.I.s exhibit variation for resistance, and 2) determine if resistance is transferable to lettuce. Seedlings were inoculated with root macerate of BV infected plants, transplanted to BV infested soil, and greenhouse grown for 3 months. Twelve plants in each of 1,2, or 3 reps of Great Lakes 65 (GL65-susceptible), Pavane (Pav-tolerant), L. virosa (11 accessions), and BC1 F2 through F5 families of lettuce cultivars x L. virosa accession IVT280 were tested. The percentage of BV afflicted plants was recorded. In hybrid families, BV free plants from tolerant families were selected and advanced. No BV was found in L. virosa. Variation for tolerance was observed in BC1 F2 and F3 families; 33% had greater tolerance than Pav (17% afflicted). Additional tests identified 11 BC1 F3 families (14%) with greater tolerance than Pav (42% afflicted). Subsequent BC1 F4 and F5 generations however, were more susceptible than Pav. Lactuca virosa is highly resistant, but resistance did not transfer to hybrid progeny. Variation for tolerance was observed in BC1 F2 and F3 families, but later generations were susceptible. Interactions or linkage of genes for developmental processes and BV resistance may hinder introgression. Introgression will continue using congruity backcrossing and a greater diversity of L. virosa.

2021 ◽  
Author(s):  
kousuke seki ◽  
kenji komatsu ◽  
masahiro hiraga ◽  
keisuke tanaka ◽  
yuichi uno ◽  
...  

Abstract Resistance to multiple races of Fusarium wilt is considered a critical trait for lettuce (Lactuca sativa L.) cultivars, as it is directly related to grower profitability in Japan. We analyzed F2 individuals obtained from a cross between ‘VI185’ (resistance to race 2) and ‘ShinanoGreen’ (susceptible to race 2), and applied a bioassay to the F3 population using the race 2 pathogen. ddRAD-seq analysis showed that a single semi-dominant locus on LG1 (qFOL1.2) controls resistance, and that the genotype of a RAD-marker designated as LG1_v8_117.181Mbp showed complete co-segregation with the resistance phenotype based on the F2 population. Fine mapping by PCR-based markers further revealed that qFOL1.2 were located in the position of 116.468-117.974Mbp. The 42 cultivars were evaluated for the genotypes and phenotypes using the PCR-based makers designed at this region. As a result of genotyping, all of the susceptible cultivars had the same genotype in this region, but the resistant cultivars had the diversity in the genotype. Notably, the genotype of the PCR-based marker designated as LG1_v8_116.506Mbp was consistent across the 25 resistant cultivars. Thus, we reasoned that LG1_v8_116.506Mbp was a broadly useful marker for selection of race 2-resistance. Our results provide additional breeding technique for resistance to race 2, and can accelerate pyramiding of resistance loci to multiple races of fusarium wilt.


Plant Disease ◽  
2007 ◽  
Vol 91 (4) ◽  
pp. 439-445 ◽  
Author(s):  
Ryan J. Hayes ◽  
Gary E. Vallad ◽  
Qing-Ming Qin ◽  
Rebecca C. Grube ◽  
Krishna V. Subbarao

Host resistance offers the most cost-effective method of Verticillium wilt control in lettuce (Lactuca sativa). In 2004 and 2005, 107 and 22 lettuce cultivars, respectively, were screened for resistance in a field infested with Verticillium dahliae, and disease progress on resistant and susceptible cultivars was determined. Greenhouse experiments were conducted to evaluate 16 cultivars for resistance to a race 1 and a race 2 isolate. Significant differences for resistance were observed within cultivated lettuce. In susceptible cultivars, disease levels increased through the season, whereas disease in resistant cultivars remained constant. Resistance in greenhouse tests was dependant upon the race used. Seven cultivars were resistant to race 1, whereas all were susceptible to race 2. Cultivar reactions to race 1 in greenhouse and field experiments were correlated, indicating the utility of greenhouse evaluations. The identification of resistance in diverse lettuce types is beneficial to the breeding process. However, because of the existence of resistance-breaking race 2 isolates, this resistance may not be durable. Alternatively, targeted releases of race-1-resistant cultivars to fields with only race 1 pathogen genotypes may extend the life of these cultivars.


1965 ◽  
Vol 43 (9) ◽  
pp. 1141-1149 ◽  
Author(s):  
R. N. Campbell

The lettuce big-vein virus (BVV) was recovered from 2 of 23 lettuce plants (Lactuca sativa L.) and 2 of 24 sow thistle (Sonchus oleraceus L.) plants sampled in 1962 and 1963 in areas of the lower Sacramento Valley where lettuce had not previously been grown. BVV is considered to be an indigenous virus of plant species in the Compositae family; these apparently are symptomless hosts and the presence of BVV is noted only when lettuce is planted under favorable environmental conditions. A BVV-Olpidium isolate from sow thistle was shown to be a physiological strain differing from the lettuce isolate in transmitting BVV to sow thistle and multiplying well in sow thistle roots. In addition, the susceptibility of Lactuca spp., Cichorium spp., and Taraxacum officinale to BVV-lettuce Olpidium was tested; only Laciuca serriola, Lactuca saligna, Cichorium sp., and a sow thistle from Japan showed good symptoms, Lactuca gracoglossum and Lactuca virosa showed symptoms poorly. Of the symptomless species, Olpidium and BVV were recovered from Lactuca muralis, T. officinale, and chicory (cv. asparagus) but not from endive (cv. No. 5) or chicory (cv. Large rooted). Sow thistle yellow-vein virus produces symptoms suggestive of big vein in sow thistle but its identity as a distinct virus transmitted by Nasonovia lactucae (L.) was confirmed.


2020 ◽  
Author(s):  
Lorena B Parra ◽  
Ivan Simko ◽  
Richard Michelmore

Lettuce downy mildew caused by Bremia lactucae Regel is the most economically important foliar disease of lettuce (Lactuca sativa L.). The deployment of resistant cultivars carrying dominant resistance genes (Dm genes) plays a crucial role in integrated downy mildew disease management; however, high variability in pathogen populations leads to the defeat of plant resistance conferred by Dm genes. Some lettuce cultivars exhibit field resistance that is only manifested in adult plants. Two populations of recombinant inbred lines (RILs), originating from crosses between the field resistant cultivars Grand Rapids and Iceberg and susceptible cultivars Salinas and PI491224, were evaluated for downy mildew resistance under field conditions. One hundred and sixty RILs from the Iceberg × PI491224 and 88 RILs from the Grand Rapids × Salinas RIL populations were genotyped using genotyping by sequencing, which respectively generated 906 and 746 high quality markers that were used for quantitative trait locus (QTL) analysis. We found a QTL in Chromosome 4 that is present in both Grand Rapids × Salinas and Iceberg × PI491224 populations that has a major effect on field resistance. We also found two additional significant QTLs in Chromosomes 2 and 5 in the Iceberg × PI491224 RIL population. Marker-assisted gene pyramiding of multiple Dm genes in combination with QTLs for field resistance provides the opportunity to develop cultivars with more durable resistance to B. lactucae.


2017 ◽  
Vol 2 (01) ◽  
pp. 115-127
Author(s):  
Siti Hilalliyah ◽  
Intan Sari ◽  
Zahlul Ikhsan

Sistem hidroponik memungkinkan sayuran ditanam di daerah yang kurang subur dan daerah sempit yang padat penduduknya. Alasan penerapan teknik hidroponik yang utama adalah karena terbatasnya lahan pertanian yang produktif untuk memenuhi kebutuhan manusia yang semakin banyak tiap tahunnya, sehingga dibutuhkan suatu terobosan baru untuk memecahkan masalah tersebut. Penelitian ini telah dilaksanakan pada bulan November 2015 sampai bulan Januari 2016 yang bertempat di kampus Fakultas Pertanian Jl. Propinsi Kecamatan Tembilahan Hulu Kabupaten Indragiri Hilir Propinsi Riau.Metode penelitian yang digunakan adalah Rancangan Acak Lengkap (RAL) pola faktorial yang terdiri dari 2 faktor. Faktor pertama adalah jenis POC (N) yang terdiri dari 3 taraf perlakuan yaitu POC Jus Bumi, POC Bonggol Pisang danPOC Limbah Sayuran. Faktor kedua adalah konsentrasi larutan (K) yang terdiri dari 3 taraf perlakuan yaitu 150 ppm, 200 ppm dan 250 ppm. Parameter pengamatan adalah Tinggi Tanaman , Jumlah Daun , Luas Daun , Diameter Batang, Panjang akar ,Volume Akar, Kadar Air, dan Bobot Hasil.Hasil pengamatan menunjukkan bahwa perlakuan jenis POC jus bumi dengan konsentrasi larutan 150 ppm memberikan pertumbuhan dan produksi terbaik untuk tanaman selada secara hidroponik sistem wick. Perlakuan jenis POC limbah sayuran dengan konsentrasi 250 ppm memberikan pertumbuhan dan produksi terbaik selain POC jus bumi sehingga dapat dijadikan sumber POC alternatif.


Author(s):  
Nguyễn Minh Trí ◽  
Nguyễn Hạnh Trinh ◽  
Nguyễn Thị Hoàng Phương

Xà lách (Lactuca sativa L.) là một loại rau ăn lá quan trọng có giá trị dinh dưỡng và kinh tế cao. Cây Xà lách có đặc điểm là loại rau ngắn ngày, có thời gian sinh trưởng ngắn khoảng từ 45 - 55 ngày, có thể phát triển tốt trên nhiều loại đất, là loại rau ăn sống được sử dụng rất phổ biến trong bữa ăn hàng ngày của người dân Việt Nam nên nó được trồng quanh năm, do vậy vấn đề về chất lượng lại càng phải được quan tâm nhiều hơn. Bài báo này giới thiệu kết quả phân tích về dư lượng nitrat và các kim loại nặng (Cu, Pb, Zn) trong rau Xà lách vụ Xuân - Hè 2012 - 2013 ở phường Hương Long - thành phố Huế. Kết quả nghiên cứu cho thấy: đất trồng rau Xà lách tại phường Hương Long – thành phố Huế đạt tiêu chuẩn về hàm lượng kim loại nặng (Pb, Zn) theo QCVN 03:2008/BTNMT, nhưng hàm lượng Cu và nitrat là khá cao. Rau Xà lách thành phẩm có dư lượng nitrat cao hơn 1,21% so với quy định và các kim loại nặng (Pb, Zn, Cu) tồn dư trong rau lại ở mức cao và vượt tiêu chuẩn cho phép nhiều lần sẽ ảnh hưởng đến sức khỏe của người sử dụng.


Author(s):  
Ferreira Gabriel Menezes ◽  
Souza Antonio Tassio de Oliveira ◽  
Souza Alisson Silva de ◽  
Gomes Igor Thiago dos Santos ◽  
Cunha Denise de Andrade

2015 ◽  
Vol 38 (4) ◽  
pp. 405
Author(s):  
Jorge A. Vázquez-Ybarra ◽  
Cecilia B. Peña-Valdivia ◽  
Carlos Trejo ◽  
Albino Villegas-Bastida ◽  
Sergio Benedicto-Valdéz ◽  
...  

Las plantas han desarrollado un conjunto de mecanismos morfológicos, bioquímicos y fisiológicos de respuesta a los cambios ambientales de O3. El objetivo de este estudio fue evaluar el efecto de dosis subletales de O3, aplicadas al medio de cultivo, en el crecimiento de plantas de lechuga (Lactuca sativa L.). Con base en el fenómeno denominado hormesis, la hipótesis fue que existe una dosis umbral de O3 que modifica positivamente el metabolismo de las plantas e incrementan su crecimiento y productividad. En un sistema hidropónico de plantas en flotación se evaluaron nueve dosis entre 0.53 y 59.40 mg L-1, aplicadas semanalmente, y se compararon con un testigo sin O3. Las variables del crecimiento que se cuantificaron fueron: diámetro del tallo, altura del tallo, altura de hoja, número total de hojas, longitud de raíz, peso fresco de raíz, biomasa seca de raíz, peso fresco y biomasa del vástago. Las plantas completaron su ciclo de crecimiento sin algún daño en el crecimiento con concentraciones entre 0.53 y 5.94 mg de O3 L-1, pero 20, 40 y 60 mg L-1 fueron letales en plantas de cinco semanas de edad. Estas dosis causaron oscurecimiento y necrosis acelerados de los tejidos foliares y muerte, los cambios de color de las hojas fueron evidentes desde los 20 min posteriores a la única aplicación de O3. Además, las dosis de 2.66 y 3.96 mg L-1 incrementaron significativamente (P ≤ 0.05) el diámetro del tallo, la biomasa fresca en la raíz y el vástago y la biomasa seca en la raíz y el vástago, en promedio 16, 23, 15, 89 y 11 % con respecto al testigo, después de 10 semanas de crecimiento.


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