Evaluasi Toleransi Plasma Nutfah Padi terhadap P Rendah di Tanah Sawah

Abstract

<p>A field experiment was conducted to assess<br />genotypic variability of tolerance and to identify tolerant<br />genotypes to low phosphorus (P) among rice germplasm on<br />lowland (paddy) rice field with low available and potential P<br />using strip plot design with three replications. P fertilization<br />(with and without added P) was assigned as horizontal factor<br />and 120 rice plant genotypes as vertical factor. Data on plant<br />height, tiller number, and shoot dryweight were collected. Low<br />P tolerance was judged by relative value i.e. observation value<br />at the plot without P treatment devided by the value at the plot<br />with P treatment. The judgement was determined based on<br />IRRI standard. Shoot P uptake of five tolerant and five<br />sensitive genotypes on no added P treatment was also<br />observed. The results showed that the germplasm exhibited<br />phenotypic and genotypic variability of low P tolerance. The<br />highest genotypic variability of tolerance was shown by the<br />value based on relative tillering number (28.7%), followed by<br />that of relative shoot dryweight (22,6%) and relative plant<br />height (7,6%). The highest broadsense heritability of tolerance<br />was shown by the value based on relative tiller number<br />(24.1%), followed by that of relative plant height (16.6%) and<br />relative shoot dry weight (15.0%) Fourteen genotypes were<br />identified as highly tolerant based on relative tiller number and<br />28 genotypes based on relative shoot dryweight. The tolerance<br />of genotype was attained by higher P uptake and higher<br />internal use efficiency.</p>