Rules for evaluation of maize for resistance to pests Part 1:Rules for evaluation of maize for resistance to northern corn leaf blight
Some standard content:
ICS65.020
Agricultural Industry Standard of the People's Republic of China
NY/T1248.1—2006
Technical Specification for Evaluation of Maize for Resistance to Diseases and Pests
Part 1: Technical Specification for Evaluation of Maize for Resistance to Northern Corn Leaf BlightRules for evaluation of maize for resistance to pestsPart 1: Rule for ewaluation of maize for resistance to northern corn leaf blightPublished on December 6, 2006
Implementation on February 1, 2007
Ministry of Agriculture of the People's Republic of China
NYTT1248 "Technical Specification for Evaluation of Maize for Resistance to Diseases and Pests" is a series of standards. Part 1: Technical specification for identification of corn resistance to northern leaf blight: Part 2: Technical specification for identification of corn resistance to small blight: Part 3: Technical specification for identification of corn resistance to head smut: Part 4: Technical specification for identification of corn resistance to dwarf mosaic: Part 5: Technical specification for identification of corn resistance to corn This part is Part 1 of NY/T1248.
Appendix A and Appendix B of this part are informative appendices. This part is proposed and managed by the Ministry of Agriculture of the People's Republic of China. NY/T1248.1—2006
Drafting units of this part: Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Institute of Plant Protection, Chinese Academy of Agricultural Sciences. Main drafters of this part: Wang Xiaoming, Dai Fachao, Zhu Zhendong, He Kanglai, Wang Xifeng. I
1 Scope
Technical specification for identification of corn resistance to diseases and insect pests
Part 1: Technical specification for identification of corn resistance to northern leaf blight This part specifies the technical methods for identification of corn resistance to northern leaf blight and the resistance evaluation standards. NY/T1248.1—2006
This standard applies to the field identification and evaluation of the resistance of cultivated maize (Zemas L.) inbred lines, hybrids, group open-pollinated varieties, as well as wild maize and maize relatives to corn leaf blight. Terms and Definitions
The following terms and definitions apply to this standard. 2.1
Disease resistance
A heritable trait of a plant that can reduce or overcome the pathogenic effects of a pathogen. 2.2
Screening for disease resistance
Identifying the resistance level of a plant to its specific infectious disease through appropriate technical methods. 2.3
Pathogenicity
Pathogenicity
The ability of a pathogen to infect a host plant and cause disease. 2.4
artificial inoculation
artificial inoculation
The process of placing the inoculum on the appropriate part of the plant by artificial manipulation under suitable conditions. 2.5
disease rating scaleThe numerical description of the degree of disease in individual plants or groups. 2.6
evaluation of resistance
The description of the degree of response and resistance level of plant hosts to specific pests and diseases based on the adopted technical standards. 2.7
isolate
isolate
Pure culture of pathogens isolated by artificial methods. 2.8
medium
medium
A natural or artificial matrix on which pathogens can grow. 2.9
inoculum
The pathogen or part of the pathogen used for inoculation to cause disease. 2.10
NY/T1248.12006
inoculumsuspension
Inoculation suspension
Liquid containing a quantitative inoculum for inoculation. 2.11
physiological race
A group of pathogenic bacteria that has no internal morphological differences but has significant pathogenicity differences in different varieties. 2.12
differential host
A set of host varieties with different resistance genes used to identify and distinguish physiological races/pathotypes/strains of specific pathogens. 2.13
Northern corn leaf blight is a major rice disease caused by Setosphaertaturcica (Luttrell) Leonard et Suggs, the asexual state is Erserohium turcicam (Pass) Leonard et Suggs, with large lesions on the leaves as the main symptom. 3 Preparation of northern corn leaf blight pathogen inoculum
3.1 Pathogen isolation
The northern corn leaf blight pathogen was isolated from the typical lesions on the leaves of the diseased plants by conventional tissue separation or single spore separation. After the isolate was confirmed to be Erserohium turcictum (Pass.) Leonard et Suggs by morphological identification, the isolate was purified and stored at 4°C for future use after pathogenicity determination. 3.2 Physiological subspecies identification
The isolate used for resistance identification inoculation was first identified by physiological subspecies identification. The host of physiological race identification uses corn materials containing different single genes for resistance to large leaf spot disease.
3.3 Inoculum propagation and preservation
The isolate used for inoculation should be the local dominant physiological race. The pathogen inoculum needs to be propagated before inoculation. The common propagation method is to inoculate the pathogen cultured on the culture medium plate on the high-pressure sterilized sorghum grains (the preparation method of sorghum grain culture medium: the sorghum grains are boiled for 30min-40min, put into a triangular flask and sterilized at 121C for 1h, cooled and set aside), and cultured in the dark at 23℃~25℃. After 5d~7d of culture, the hyphae are all over the sorghum grains. Wash the mycelium on the surface of the sorghum grains with water, then spread it on a clean porcelain plate, maintain high humidity, and culture it at room temperature and dark conditions. After confirming that a large number of conidia are produced by microscopic examination, the sorghum grains are directly washed with water to prepare the inoculation suspension. The conidia concentration in the suspension is adjusted to 1×105/ml~1×10°/ml. If not inoculated temporarily, the spore-producing sorghum grains will be gradually dried in the shade and stored under dry media conditions or refrigerated. Take out the preserved sorghum grains before inoculation to keep them moist and promote the spore production of the large spot pathogen. The sorghum grains with bacteria should be used in the same year. 4 Resistance identification solid setting
4.1 Identification plaque
The identification plaque should have a good natural disease environment4.2 Identification design
The identification materials are arranged randomly or sequentially, and a group of known disease-resistant, disease-susceptible and highly susceptible control materials is set for every 50 to 100 identification materials4.3 Planting requirements
The sowing time of the identification materials is the same as the sowing time of field production or is appropriately adjusted so that the plant inoculation period and disease period can meet the appropriate climatic conditions (humidity and temperature).
The identification plot has a row length of 4m~5m, a row spacing of 0.7m, and 25 to 30 seedlings are left in each row, and the spacing is slightly smaller than that of field production. When identifying resources, plant one row for each identification material: when identifying varieties, repeat each material twice. Soil fertility level and tillage management are the same as those for field production. 2
5 Inoculation
5.1 Inoculation period
NY/T1248.1—2006
The inoculation period is from the 13-leaf stage to the early tasseling stage of corn. Early-maturing varieties should be inoculated at the 10-leaf stage. The inoculation time is selected in the late season.
Inoculation method
Inoculation adopts the spray method. Add 0.01% Tween (v/v) to the filtered and adjusted inoculation suspension. Spray inoculate the leaves of the plants, and control the inoculation amount at 5ml/plant to 10ml/plant. 5.3 Field management before and after inoculation
Identification Field irrigation should be carried out before inoculation or inoculation should be carried out after rain. If there is continuous dry weather after inoculation, field irrigation should be carried out in time to ensure that the conditions required for the occurrence of diseases are met.
6 Disease investigation
Investigation time
Investigation will be conducted when corn enters the late milky stage. 6.2
Investigation method
Visually inspect the disease status of each identification material group. The key parts are the three leaves above and below the corn ear. According to the description of the disease symptoms, record the disease level of each material. 6.3
3 Disease classification
The field disease classification and corresponding symptom descriptions are shown in Table 1, and the proportion of lesions to leaf area is shown in Figure 1. Table 1 Classification of disease levels for identification of corn resistance to large leaf spot Disease level
Symptom description
There are no lesions on leaves or only sporadic lesions on leaves below the ear, and the lesions account for less than or equal to 5% of the leaf area. There are a small number of lesions on leaves below the ear, accounting for 6%-10% of the leaf area, and there are sporadic lesions on leaves above the ear. There are more lesions on leaves below the ear, accounting for 11%-30% of the leaf area, and there are a small number of lesions on leaves above the ear. There are a large number of lesions on leaves below the ear or leaves above the ear, and the lesions are connected, accounting for 31%-70% of the leaf area. The entire spine is basically covered with lesions, and 5% of the leaves are dead
Schematic diagram of the proportion of lesions to leaf area
NY/T1248.1-2006
Resistance evaluation
Judgment of identification validity
When the susceptible or highly susceptible control materials set reach their corresponding susceptibility level (level 7 or 9), the identification of this batch is deemed valid. Resistance evaluation standards
The resistance level of the identified materials shall be determined according to the disease severity (disease level). The classification standards are shown in Table 2. Table 2
Disease severity classification
Repeated identification
Evaluation standards for corn resistance to northern leaf blight
Highly resistant (HR)
Resistant (R)
Modlerately resistant (MR) suraceprible(s)
Highly susceptible (HS)
If the resource materials are initially identified as highly resistant, resistant, or moderately resistant, the identification shall be repeated the following year. 7.4 Resistance evaluation
Disease resistance of the identified materials shall be evaluated based on the results of repeated resistance identification. The resistance shall be based on the highest disease level recorded. 8
Identification record form
The record form of corn resistance to northern leaf blight identification results is shown in Table 3. Table 3
Note 1: Identification site
Variety/germplasm name
Note 2: Isolate number of inoculated pathogen
Note 3: Inoculation date
Record table of identification results of maize resistance to northern leaf blight in 2017 Source
Physiological race and beautiful type
Adjustment period
Disease level
Resistance evaluation
Identification technical person in charge (signature):
A.1 Scientific name and morphological description
A.1.1 Asexual state
Appendix A
Informative appendix
Pathogen and physiological race of maize northern leaf blight
Erserohilum tureicum, scientific name: Erserohilum tureicum (Pass.) Leonardet Suggs Synonym: Helminthosporium turcicum Pass. Bipolaris turcica (Pass.) Shoemaker Drechsleraturcica (Pass,) Subramanian et Jain Helminthosporituminconspicum Cooke et Ellis NY/T1248.1—2006
On natural lesions, the pathogenic fungus conidiophores are solitary or clustered in 2 to 6, generally unbranched, straight or knee-shaped, brown, up to 300m long, 7gm to 11m wide, with swollen basal cells, with obvious spore scars left after sporulation at the top or knee-shaped bend, and 2 to 8 septa. Conidia are straight or slightly curved, long fusiform, light brown or gray-olive, gradually narrowed at both ends, with blunt-rounded apical cells and conical basal cells with 2 to 7 pseudosepta, 50-144m×15~23m, and the spore hilum is obvious and protrudes outside the basal cells. Germ tubes are produced at both ends during germination.
A.1.2 Sexual state
Setosphaeria Tarczca (Luttrell) Leonardet Suggs Synonyms: Trichometasphaeria turcica Luttrell Keissleriella turcica (Luttrell) Arx Trichomretasphaeria tarczca Luttrell f.sp. sorghi Bergquist et Masias Trichonetasphaeria furcica Luttrell f.sp. zee Bergquist et Masias Ascospores are formed on the surface of host tissues. Ascospores are black and oval, with short and hard brown bristles on the upper part of the outer wall. There are lateral threads in the ascospore cavity. Asci are barrel-shaped or clavate, with short handles, 161rcm×27um, double-walled, containing 1 to 6 or 2 to 4 ascospores. Ascospores are colorless, sometimes brown, nearly spindle-shaped, straight or slightly curved, with 1 to 5 septa, mostly 3, constricted at the septa, with an average size of 52.7pm×14.1em, and the surface is covered by a long and thin mucous sheath. 5
NY/T1248.1—2006
Identification control materials
Appendix B
【Informative Appendix】
Control varieties and physiological races of pathogens for identification of resistance to corn leaf blight The control materials used for resistance identification are 4 inbred lines: QI 319 (resistant), MIo17 (medium resistant), CA091 (susceptible), Hubai (highly susceptible), B.2 physiological race
B.2.1 Identification hosts used
Huang Zao Si Huang Zao Si H1, Huang Zao Si H2, Huang Zao Si H3, Huang Zao Si or other materials containing different resistance genes, such as B73, B73HB73H2, B73H3 B73HtN
B.2.2 Identification of physiological races
The resistance response is determined based on the lesion type after inoculation on the identification host, and the physiological races are divided according to specific reaction combinations (Table B.1). Table B.1
Physiological race name
Physiological race identification of the pathogen of corn leaf blight Resistance gene reaction type
Toxicity formula
(Effective disease resistance gene/ineffective disease resistance gene)
Htl H2 Ht3 Htn/D
H2H3HN/Hul
Ht1 Htv/H2 Ht3
Hl/H12 Ht3 Hty
Ht1 Ht3/H2 Hey
Note: Slightly improved on the physiological race naming method of Leonard (1989): \S\ is ginger-type lesions, "Rc\ is chlorotic lesions, and "Rv\ is no lesion type reaction4 Resistance evaluation
Evaluate the disease resistance of the identified materials based on the repeated resistance identification results. The resistance is based on the highest disease level recorded. 8
Identification record form
See Table 3 for the record form of corn resistance to northern leaf spot disease. Table 3
Note 1: Identification site
Variety/germplasm name
Note 2: Isolate number of inoculated pathogen
Note 3: Inoculation date
Record table of identification results of maize resistance to northern leaf blight in 2017 Source
Physiological race and beautiful type
Adjustment period
Disease level
Resistance evaluation
Identification technical person in charge (signature):
A.1 Scientific name and morphological description
A.1.1 Asexual state
Appendix A
Informative appendix
Pathogen and physiological race of maize northern leaf blight
Erserohilum tureicum, scientific name: Erserohilum tureicum (Pass.) Leonardet Suggs Synonym: Helminthosporium turcicum Pass. Bipolaris turcica (Pass.) Shoemaker Drechsleraturcica (Pass,) Subramanian et Jain Helminthosporituminconspicum Cooke et Ellis NY/T1248.1—2006
On natural lesions, the pathogenic fungus conidiophores are solitary or clustered in 2 to 6, generally unbranched, straight or knee-shaped, brown, up to 300m long, 7gm to 11m wide, with swollen basal cells, with obvious spore scars left after sporulation at the top or knee-shaped bend, and 2 to 8 septa. Conidia are straight or slightly curved, long fusiform, light brown or gray-olive, gradually narrowed at both ends, with blunt-rounded apical cells and conical basal cells with 2 to 7 pseudosepta, 50-144m×15~23m, and the spore hilum is obvious and protrudes outside the basal cells. Germ tubes are produced at both ends during germination.
A.1.2 Sexual state
Setosphaeria Tarczca (Luttrell) Leonardet Suggs Synonyms: Trichometasphaeria turcica Luttrell Keissleriella turcica (Luttrell) Arx Trichomretasphaeria tarczca Luttrell f.sp. sorghi Bergquist et Masias Trichonetasphaeria furcica Luttrell f.sp. zee Bergquist et Masias Ascospores are formed on the surface of host tissues. Ascospores are black and oval, with short and hard brown bristles on the upper part of the outer wall. There are lateral threads in the ascospore cavity. Asci are barrel-shaped or clavate, with short handles, 161rcm×27um, double-walled, containing 1 to 6 or 2 to 4 ascospores. Ascospores are colorless, sometimes brown, nearly spindle-shaped, straight or slightly curved, with 1 to 5 septa, mostly 3, constricted at the septa, with an average size of 52.7pm×14.1em, and the surface is covered by a long and thin mucous sheath. 5
NY/T1248.1—2006
Identification control materials
Appendix B
【Informative Appendix】
Control varieties and physiological races of pathogens for identification of resistance to corn leaf blight The control materials used for resistance identification are 4 inbred lines: QI 319 (resistant), MIo17 (medium resistant), CA091 (susceptible), Hubai (highly susceptible), B.2 physiological race
B.2.1 Identification hosts used
Huang Zao Si Huang Zao Si H1, Huang Zao Si H2, Huang Zao Si H3, Huang Zao Si or other materials containing different resistance genes, such as B73, B73HB73H2, B73H3 B73HtN
B.2.2 Identification of physiological races
The resistance response is determined based on the lesion type after inoculation on the identification host, and the physiological races are divided according to specific reaction combinations (Table B.1). Table B.1
Physiological race name
Physiological race identification of the pathogen of corn leaf blight Resistance gene reaction type
Toxicity formula
(Effective disease resistance gene/ineffective disease resistance gene)
Htl H2 Ht3 Htn/D
H2H3HN/Hul
Ht1 Htv/H2 Ht3
Hl/H12 Ht3 Hty
Ht1 Ht3/H2 Hey
Note: Slightly improved on the physiological race naming method of Leonard (1989): \S\ is ginger-type lesions, "Rc\ is chlorotic lesions, and "Rv\ is no lesion type reaction4 Resistance evaluation
Evaluate the disease resistance of the identified materials based on the repeated resistance identification results. The resistance is based on the highest disease level recorded. 8
Identification record form
See Table 3 for the record form of corn resistance to northern leaf spot disease. Table 3
Note 1: Identification site
Variety/germplasm name
Note 2: Isolate number of inoculated pathogen
Note 3: Inoculation date
Record table of identification results of maize resistance to northern leaf blight in 2017 Source
Physiological race and beautiful type
Adjustment period
Disease level
Resistance evaluation
Identification technical person in charge (signature):
A.1 Scientific name and morphological description
A.1.1 Asexual state
Appendix A
Informative appendix
Pathogen and physiological race of maize northern leaf blight
Erserohilum tureicum, scientific name: Erserohilum tureicum (Pass.) Leonardet Suggs Synonym: Helminthosporium turcicum Pass. Bipolaris turcica (Pass.) Shoemaker Drechsleraturcica (Pass,) Subramanian et Jain Helminthosporituminconspicum Cooke et Ellis NY/T1248.1—2006
On natural lesions, the pathogenic fungus conidiophores are solitary or clustered in 2 to 6, generally unbranched, straight or knee-shaped, brown, up to 300m long, 7gm to 11m wide, with swollen basal cells, with obvious spore scars left after sporulation at the top or knee-shaped bend, and 2 to 8 septa. Conidia are straight or slightly curved, long fusiform, light brown or gray-olive, gradually narrowed at both ends, with blunt-rounded apical cells and conical basal cells with 2 to 7 pseudosepta, 50-144m×15~23m, and the spore hilum is obvious and protrudes outside the basal cells. Germ tubes are produced at both ends during germination.
A.1.2 Sexual state
Setosphaeria Tarczca (Luttrell) Leonardet Suggs Synonyms: Trichometasphaeria turcica Luttrell Keissleriella turcica (Luttrell) Arx Trichomretasphaeria tarczca Luttrell f.sp. sorghi Bergquist et Masias Trichonetasphaeria furcica Luttrell f.sp. zee Bergquist et Masias Ascospores are formed on the surface of host tissues. Ascospores are black and oval, with short and hard brown bristles on the upper part of the outer wall. There are lateral threads in the ascospore cavity. Asci are barrel-shaped or clavate, with short handles, 161rcm×27um, double-walled, containing 1 to 6 or 2 to 4 ascospores. Ascospores are colorless, sometimes brown, nearly spindle-shaped, straight or slightly curved, with 1 to 5 septa, mostly 3, constricted at the septa, with an average size of 52.7pm×14.1em, and the surface is covered by a long and thin mucous sheath. 5
NY/T1248.1—2006
Identification control materials
Appendix B
【Informative Appendix】
Control varieties and physiological races of pathogens for identification of resistance to corn leaf blight The control materials used for resistance identification are 4 inbred lines: QI 319 (resistant), MIo17 (medium resistant), CA091 (susceptible), Hubai (highly susceptible), B.2 physiological race
B.2.1 Identification hosts used
Huang Zao Si Huang Zao Si H1, Huang Zao Si H2, Huang Zao Si H3, Huang Zao Si or other materials containing different resistance genes, such as B73, B73HB73H2, B73H3 B73HtN
B.2.2 Identification of physiological races
The resistance response is determined based on the lesion type after inoculation on the identification host, and the physiological races are divided according to specific reaction combinations (Table B.1). Table B.1
Physiological race name
Physiological race identification of the pathogen of corn leaf blight Resistance gene reaction type
Toxicity formula
(Effective disease resistance gene/ineffective disease resistance gene)
Htl H2 Ht3 Htn/D
H2H3HN/Hul
Ht1 Htv/H2 Ht3
Hl/H12 Ht3 Hty
Ht1 Ht3/H2 Hey
Note: Slightly improved on the physiological race naming method of Leonard (1989): \S\ is ginger-type lesions, "Rc\ is chlorotic lesions, and "Rv\ is no lesion type reaction1
Physiological race name
Physiological race identification of corn leaf blight pathogen Resistance gene reaction type
Toxicity formula
(Effective resistance gene/ineffective resistance gene)
Htl H2 Ht3 Htn/D
H2H3HN/Hul
Ht1 Htv/H2 Ht3bZxz.net
Hl/H12 Ht3 Hty
Ht1 Ht3/H2 Hey
Note: Slightly improved on the physiological race naming method of Leonard (1989): \S\ is ginger-type lesions, "Rc\ is chlorotic lesions, and "Rv\ is no lesion type reaction1
Physiological race name
Physiological race identification of corn leaf blight pathogen Resistance gene reaction type
Toxicity formula
(Effective resistance gene/ineffective resistance gene)
Htl H2 Ht3 Htn/D
H2H3HN/Hul
Ht1 Htv/H2 Ht3
Hl/H12 Ht3 Hty
Ht1 Ht3/H2 Hey
Note: Slightly improved on the physiological race naming method of Leonard (1989): \S\ is ginger-type lesions, "Rc\ is chlorotic lesions, and "Rv\ is no lesion type reaction
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