[NIRS for Predicting Nutritive Value of Elymus sibiricus].

Siberian wildrye (Elymus sibiricus L.) is one of the predominant pasture species in Qinghai-Tibet plateau of China. It supplies a large number of fodders to domestic animals in spring and winter, and provides a large proportion of the summer and autumn grazing in these alpine regions. Crude protein (CP), acid detergent fiber (ADF), neutral detergent fiber (NDF) and in vitro dry matter digestibility (IVDMD) are the most important aspects of nutritive value of forages. A successful application of near infrared spectroscopy (NIRS) in combination with partial least square regression (PLSR) for the determination of four parameters (CP, ADF, NDF and IVDMD) of Siberian wildrye was developed. The standard errors of calibration (SEC, %DM) and Rcal(2) values (in parentheses) were 0.3299(0.9945), 0.7799(0.9499), 1.3430(0.9133), and 1.3762(0.9822) for CP, ADF, NDF and IVDMD equations, respectively. The standard errors of prediction (SEP, %DM) and Rval(2) values (in parentheses) were 0.3621(0.9938), 0.7878(0.9449), 1.3852(0.8907), and 1.4303(0.9790) for CP, ADF, NDF and IVDMD, respectively. A good correlation (r>0.9438) was found between results from NIRS and the traditional chemical method, and residual predictive deviation (RPD) ranged from 3.02 to 12.63. It was concluded that NIR spectroscopic technique associated with chemometrics is sufficiently sensitive to allow the accurate prediction of the concentrations of compo nents (CP, ADF and NDF) and IVDMD of Siberian wildrye.

Molecular insights of genetic variation in Erianthus arundinaceus populations native to China.

BACKGROUND: E. arundinaceus (Retz.) Jeswiet is a warm-season, tall-growing perennial species native to much southern portion in China. The grass has been extensively used in sugarcane breeding and is recently targeted as a bioenergy feedstock crop. However, information on the genetic structure of the Chinese wild germplasm is limited. Knowledge of genetic variation within and among populations is essential for breeding new cultivars in the species. The major objective of this study was to quantify the magnitude of genetic variation among and within natural populations in China. METHODOLOGY/PRINCIPAL FINDINGS: In this experiment, we analyzed genetic variation of 164 individuals of 18 populations collected from natural habitats in six Chinese provinces using 20 sequence-related amplified polymorphism (SRAP) primer pairs generating 277 polymorphic bands. Among and within the populations, the percentage of polymorphic bands (PPB) was 80.00% and 27.07%, genetic diversity (HE ) was 0.245 and 0.099, effective number of alleles (NE ) was 1.350 and 1.170, and Shannon's information index (I) was 0.340 and 0.147, respectively. The populations were clustered into six groups exhibiting a high level of genetic differentiation, which was highly associated with geographic origins of respective germplasm populations, but was not significantly associated with geographic distances between the populations. CONCLUSIONS/SIGNIFICANCE: This is the first report indicating that large genetic variation exists in the Chinese E. arundinaceus germplasm based on the SRAP molecular marker analysis of native populations. The genetic structure of populations in the species has been substantially affected by geographic landforms and environments. The diverse collection will be highly valuable in genetic improvement in the species per se and likely in sugarcane.

[Application of near infrared spectroscopy technology (NIRS) in forage field].

The majority of nutrients in ruminants and other herbivores come from forages. Forage quality not only affects the growth and production efficiency of livestock, but also determines the final output and quality of livestock products. Forage quality mainly depends on nutrient concentrations and their digestibility, palatability and the level of presence of antiquality factors and mycotoxins in forage. Near infrared reflectance spectroscopy (NIRS) has been widely used in many research areas because it is a inexpensive, rapid, simple and nondestructive technique offering the potential for qualitative and quantitative analysis. The present paper briefly introduces the principle and characteristics of NIRS, detailedly expounds the application of NIRS in forage quality. In addition, other applications of near infrared spectroscopy technique in forage are also discussed, including forage breeding, identification of variety and classification by kind. This paper comprehensively reviews the status quo of application of NIRS in forage filed, in order to contribute to promoting development of NIRS in this field in China.