Selection of lines of lettuce (Lactuca sativa L.) with a high level of partial resistance to Myzus persicae (Sulzer)

Euphytica ◽  
1988 ◽  
Vol 37 (3) ◽  
pp. 241-245 ◽  
Author(s):  
K. Reinink ◽  
F. L. Dieleman ◽  
R. Groenwold
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.


2020 ◽  
Author(s):  
German Sandoya ◽  
Maria-José Truco ◽  
Lien D Bertier ◽  
Krishna V Subbarao ◽  
Ivan Simko ◽  
...  

Lettuce (Lactuca sativa L.) is one of the most economically important vegetables in the USA with approximately 50% of the domestic production concentrated in the Salinas Valley of California. Verticillium wilt, caused by races 1 and 2 of the fungal pathogen Verticillium dahliae Kleb., poses a major threat to lettuce production in this area. While resistance governed by a single dominant gene against race 1 has previously been identified and is currently being incorporated into commercial cultivars, identification of resistance against race 2 has been challenging and no lines with complete resistance have been identified. In this study, we screened germplasm for resistance and investigated the genetics of partial resistance against race 2 using three mapping populations derived from crosses involving Lactuca sativa × L. sativa and L. serriola × L. sativa. The inheritance of resistance in Lactuca species against race 2 is complex but a common quantitative trait locus (QTL) on linkage group 6, designated qVERT6.1 (quantitative Verticillium dahliae resistance on LG 6, first QTL), was detected in multiple populations. Additional race 2 resistance QTLs located in several linkage groups were detected in individual populations and environments. Because resistance in lettuce against race 2 is polygenic with a large genotype by environment interaction, breeding programs to incorporate these resistance genes should be aware of this complexity as they implement strategies to control race 2.


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.


Author(s):  
Sri G. Thrumurthy ◽  
Tania Samantha De Silva ◽  
Zia Moinuddin ◽  
Stuart Enoch

Specifically designed to help candidates revise for the MRCS exam, this book features 350 Single Best Answer multiple choice questions, covering the whole syllabus. Containing everything candidates need to pass the MRCS Part A SBA section of the exam, it focuses intensively on the application of basic sciences (applied surgical anatomy, physiology, and pathology) to the management of surgical patients. The high level of detail included within the questions and their explanations allows effective self-assessment of knowledge and quick identification of key areas requiring further attention. Varying approaches to Single Best Answer multiple choice questions are used, giving effective exam practice and guidance through revision and exam technique. This includes clinical case questions, 'positively-worded' questions, requiring selection of the most appropriate of relatively correct answers; 'two-step' or 'double-jump' questions, requiring several cognitive steps to arrive at the correct answer; as well as 'factual recall' questions, prompting basic recall of facts.


Agriculture ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 315
Author(s):  
Noémi Kappel ◽  
Ildikó Fruzsina Boros ◽  
Francia Seconde Ravelombola ◽  
László Sipos

The goal of this research was to investigate the effect of electrical conductivity (EC) levels of the nutrient solution on the fresh weight, chlorophyll, and nitrate content of hydroponic-system-grown lettuce. The selected cultivars are the most representative commercial varieties grown for European markets. Seven cultivars (‘Sintia,’ ‘Limeira,’ ‘Corentine,’ ‘Cencibel,’ ‘Kiber,’ ‘Attiraï,’ and ‘Rouxaï’) of three Lactuca sativa L. types’ (butterhead, loose leaf, and oak leaf) were grown in a phytotron in rockwool, meanwhile the EC level of the nutrient solutions were different: normal (<1.3 dS/m) and high (10 dS/m). The plants in the saline condition had a lower yield but elevated chlorophyll content and nitrate level, although the ‘Limeira’ and ‘Cencibel’ cultivars had reduced nitrate levels. The results and the special characteristic of the lollo-type cultivars showed that the nitrate level could be very different due to salinity (‘Limeira’ had the lowest (684 µg/g fresh weight (FW)) and ‘Cencibel’ had the highest (4396 µg/g FW)). There was a moderately strong negative correlation (−0.542) in the reverse ratio among the chlorophyll and nitrate contents in plants treated with a normal EC value, while this relationship was not shown in the saline condition. Under the saline condition, cultivars acted differently, and all examined cultivars stayed under the permitted total nitrate level (5000 µg/g FW).


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